This is just a casual mill deck I decided to build because I like the mill concept, but it seems to work very well against most decks. Particularly those with lots of creatures, which is usually a big weakness of mill (Wight of Precinct Six seems a very underplayed card; Avatar of Woe drops quickly, and is great for removing threats).
The milling sorceries need no explanation - they are the core of the deck.
When first constructing the deck, I used Hedron Crabs, but I really don't like them. They're too easy to kill, don't mill very much, and are otherwise useless. So Snapcaster Mages quickly took their place for obvious reasons.
Propaganda is a crucial inclusion to prevent it being overrun. Go for the Throat / Doom Blade provides extra protection.
Visions of Beyond is there because often towards the end of the game your hand is all but empty - three cards for one mana solves that problem, although I have considered just having something like Preordain in, which is more useful earlier on. Thought Scour also gives a small mill and a card draw but just doesn't seem worthy of inclusion.
Jace, Memory Adept is a great card, but it's 5 mana, and I don't think it's needed.
Crypt Incursion obviously doesn't work very well with Jace's Phantasm or Wight of Precinct Six, but it can be very useful buying time with all that life. It's also a way of dealing to some extent with the Eldrazi, as is Surgical Extraction. Maybe Lazav, Dimir Mastermind would be another card to swap in against those.
The only major problem card that the deck really struggles to deal with, though, is Leyline of Sanctity. No targeting an opponent pretty much kills the deck. This is why I've considered cards like Laboratory Maniac (although not great), and also the somewhat cumbersome combination of Echoing Truth and Spell Pierce, given that they don't even have to cast it if it's in their opening hand. Not really sure how else to get round it without overhauling the deck (I don't think Nemesis of Reason is the answer) so any suggestions on that front are welcome!
As I say, just a casual deck, but hope you like it. Please rate it, and leave any comments on how you think it can be improved!