First of all let's start with typical ways of building
Tasigur, the Golden Fang in the Casual EDH format.
Some of the most known Tasigur lists in this format consist of:
Lands-Matter
Going with this strategy and style you should go very heavy on lands and think of your budget since some of the best lands are not cheap. (Like Gaea's Cradle and all of the original dual lands.) But in the end you might not even end up needing such cards, because these days there are better options to most of the best lands that MTG has to offer. Like the said Gaea's Cradle can be easily replaced with the budget verion Growing Rites of Itlimoc
This playstyle can benefit from most of the lands and since most of the dual lands are what people like to call "tap-lands" (that enter the battlefield tapped) Amulet of Vigor is a good include to your deck.
With Lands-Matter you should really focus on getting a high count of lands to the field as fast as possible, so the next thing you should include is the mana-ramp. Exclude most of the artifacts and mana dorks to give more space for cards like Rampant Growth, Cultivate, Kodama's Reach, Skyshroud Claim and Farseek.
The best mana searching card for this deck and almost an auto-include is the card called Crop Rotation since it is at the same time a mana ramp card (if searching for a card like Gaea's Cradle or Cabal Coffers) and a reactive card (if searching for a card like Bojuka Bog or Strip Mine)
With this strategy you should invest on the fetch lands and shock lands, since fetch lands are recurable with cards like Life from the Loam.
Some other cards that I would really recommend for this kind of play style are Splendid Reclamation, Life from the Loam, Ramunap Excavator, Burgeoning, Exploration, Crucible of Worlds and Azusa, Lost but Seeking
Of course with all decks you're going to need a pay off for all the lands you're going to hoard on the field. Some good pay offs are Torment of Hailfire, Avenger of Zendikar and Villainous Wealth.
Now there is one well known Youtuber who has made a great video about this kind of style that you definitely should go watch if this tickles your fancy. It's from the great man himself Jumbo Commander and please give some respect for the guy since he really nailed it for this style.
The video can be watched from this link: https://www.youtube.com/watch?v=e-CfPRlKfyM or if you don't feel like clicking any links in other sites you can search for it on Youtube with: "Jumbo Commander Tasigur Lands"
Discard
Going with this strategy is not optimal in my opinion, since you're not going to get much value for this strategy with your commander. Your enemies will never like the idea of you getting discard cards back from your graveyard to your hand and will always give the worst (for you) options to give back.
You could try to go with some flavour cards with this, like putting in the Tasigur's Cruelty and of course I'd recommend putting cards like Thoughtseize, Duress, Hymn to Tourach, Dark Deal and something that you benefit from the enemies discarding cards like Bloodchief Ascension, Waste Not, Liliana's Caress, Geth's Grimoire and Bone Miser.
In the end I wouldn't go for this kind of strategy with this commander. Nekusar, the Mindrazer is so much better commander for this style.
Mill
This is another style that I would not go because it doesn't win that consistently, but since we're talking about Casual EDH Tasigur, the Golden Fang can manage this style with the best mill color combination of Dimir. This is why you should just keep the green's colour identity just for ramping and artifact/enchantment removal. You could ofcourse tutor the best mill strategy creatures like Consuming Aberration with cards like Worldly Tutor and Finale of Devastation.
Some of the best cards for this kind of style are cards that will ofcourse force opponents to mill cards in huge amounts. The best card to go for in my opinion is Mind Grind since if it would resolve it's effect can be devastating if the X Cost is close to 7-10. Now there are a lot of different kinds of mill cards and in the end it really depends on your own preferences. What you should keep in mind still is the fact that Tasigur, the Golden Fang can (in the best case scenario) use the same cards again for ever better effects.
Now that you've finally gotten the enemies graveyards big enough what if you'd use the best cards that they have in there yourself? There is a good card for this in the colour identity of Dimir called Mnemonic Betrayal from the GRN block.
With this style you should just be carefull if the enemy has any kind of re-shuffle effects like the big Eldrazi titans Kozilek, Butcher of Truth and Ulamog, the Infinite Gyre.
Self-Mill
Now going for the self-mill strategy you should know that the enemies will not like your typical win condition which'll be Laboratory Maniac, Jace, Wielder of Mysteries and/or the new mostly hated card Thassa's Oracle
You should consider cards like Hermit Druid and Mesmeric Orb with Basalt Monolith but these cards mainly assemble the more competitive combo line that uses Necrotic Ooze and some tap and untap shenanigans to gain infinite mana, so for casual style this is not the best option.
To go for more casual style with this strategy add some Reanimate like spells and start using your graveyard for value more than for instant victory lines. Some cards that I'd suggest you to try are Jarad, Golgari Lich Lord with a card called Lord of Extinction.
This style is the best to go with the next common ways of building the deck: The Dredge and the Delve
Dredge
Thankfully for this kind of style Tasigur, the Golden Fange might just be one of the best commanders to go to since the best dredge cards are in black and green and then you have the added utility power of blue at your disposal when you feel like it.
The best cards for this style are Life from the Loam, Golgari Grave-Troll, Dakmor Salvage, Stinkweed Imp and Golgari Thug. As you do see in the names of some of the cards, yes you should go more Golgari heavy with this style and do try to look up for some good Dredge combos online to go with...
Ofcourse I wouldn't just leave you with "Search for yourself", since that would be counterproductive and wold contradict with this articles main goal, which is to give you some guidelines to go for when brewing a Tasigur, the Golden Fang deck.
One of the best combos for Dredge styles uses the other well known commander The Gitrog Monster and he should be as the hidden commander in your deck with Tasigur, the Golden Fang on the lead. The combo can be hard to understand but when you master it you are going to change your commander to The Gitrog Monster since the combo is deadly and consistent.
The Gitrog Monster Dredge combo:
1st: Have The Gitrog Monster on the field.
2nd: Have a discard outlet on the field like Noose Constrictor.
3rd: Discard the Dakmor Salvage with any discard outlet.
4th: The Gitrog Monster trigger goes on the stack to draw a card.
5th: Instead of drawing just dredge Dakmor Salvage back to your hand.
6th: Repeat this process untill you hit a re-shuffler effect like Kozilek, Butcher of Truth to start the whole loop again.
7th: You're going to hit some lands on the way that go to the graveyard as you dredge, resolve some of these draw triggers to draw a card, now in the end you're going to have every card in your hand that you don't really need and you can start looping the main 5 cards as the only cards in your library and graveyard.
These cards are just some of the many possibilities with The Gitrog Monster
- Praetor's Grasp
- Kozilek, Butcher of Truth
- Lotus Petal
- Dakmor Salvage
- Any land
Just do the loop as many times as you want drawing a card with the other land card that you can just discard back to the graveyard if needed for more The Gitrog Monster triggers.
8th: Cast Lotus Petal and use it to gain a mana of any color to your mana pool.
9th: Do this loop untill you gain infinite mana
10th: Cast Praetor's Grasp infinite amount of times untill your enemies have no cards in libraries and use their win cons or just pass the turn when finished.
I know I am not the best at describing this combo, since I really don't use The Gitrog Monster but if you have more questions go watch a The Gitrog Monster deck tech by the Lab Maniacs. It'll explain the combo in greater detail.
The link for that video can be found here: https://www.youtube.com/watch?time_continue=1&v=_249jkteUaQ&feature=emb_logo
Delve
Now going with a this style Tasigur, the Golden Fang seems like it was meant to be the delve commander for EDH since Tasigur, the Golden Fang itself has the delve ability. Just so you know, yes the commander tax can be paid by delving too, since you're still casting the same card and paying the cost with colourless mana.
Now the best ways to go with this is to have some great cards that have delve ability in them. Usually what comes in mind are cards like Dig Through Time and Treasure Cruise that have huge converted mana cost's but since they can be delved they really cost maybe 2 or 3 mana max. This means that delve style can really use the aid from dredging and/or self-milling.
I really think that if you want to go this way, you should build your deck to be more like Tasigur, the Golden Fang goodstuff. Maybe put cards with very high cmc but huge pay offs like Aminatou's Augury and Villainous Wealth. The main idea with delve style is to be able to cast big spells that will help you in the long game.
With this style try to find cards that synergises with high cmc cards like Metallurgic Summonings.
Politics
Now if you really like your friends and don't want to be the asshole of the table maybe this is the way to go. You can do this 2 ways, either politics as in Group-Hug or politics as in Situational-Value
Both of these ways work with Tasigur, the Golden Fang very well, because of the 2nd ability. You should use this ability to the most with this kind of play style and since you're really going to abuse it you need to have some mana doublers, re-shufflers, cards that lower activation cost's and some cards that are juicy enough for your opponents to give you back.
Some cards that I'd really suggest you put for this kind of deck are: Seedborn Muse, Wilderness Reclamation for untapping lands to using the ability again on your opponents turns. Training Grounds, Biomancer's Familiar for activation cost reducers and cards like Timetwister, Day's Undoing, Commit / Memory to reshuffle your graveyard to your library.
End thoughts:
Now what you should know when building a casual EDH deck, these styles that I have just listed for you can be mixed and matched together, like Self-Mill and Delve. You should always go with the way that you find the most fun and you shouldn't follow only my guidelines on how to build this deck.
Tasigur, the Golden Fang can really be a great casual EDH commander for great fun because of it's possibility to use reactive cards again and again (if the enemies of your enemies want you to have them) for huge value. Remember to use the abilities of Tasigur, the Golden Fang whenever you have mana just sitting around and you and your friends will have some great fun going to games again and again.
