Your opening hand will tell you much about how you should be playing your early turns and even sometimes, your mid to late game turns. You almost always want at least two lands in hand, one being a
Forest as around 75% of the deck has
in it's cost. You want to have at least one of your Scouts,
Llanowar Scout and
Sakura-Tribe Scout and/or a
Crop Rotation. This will let you go grab your utility lands or just to play out some early disruption.
ie. Playing a Forest into a Crop Rotation to grab a Bokuja Bog if our opponent is over relying on their graveyard.
We rely on our graveyard a decent amount, but we won't just be blown out of the game if it gets removed.
That was why I enjoyed the Golgari build, but it relied on it's graveyard too much and Bojuka Bog can be played in any deck. Graveyard hate is real in Pauper.
So, as long as your opening hand has some early turn plays, you can probably keep the hand. The only forceful mulligans I would suggest is if you drew too many of your utility lands in your opening hand. Crop Rotation is easily one of the best cards we can use to "get" our opponents when they aren't prepared and/or not expecting us to be able to react very early and if you have too many of the utility lands, such as Bokuja Bog or Sejiri Steppe, in your opening hand, I would asses what you're playing against and make a mindful decision if it is okay to mulligan.
