I play Mistborn with my dad a lot. We prefer Co-Op, and there are a few strats that I thought would be cool to share, and it would be cool to hear some other strats. Here are some:
1. Specialize. I like to choose a single character (usually Kelsier) and specialize. I only take Iron and Steel cards (sometimes healing, but that's less important) and how I like to play is by choosing the mission cards, so I choose the (hot take) canton of orthodoxy to get rid of (another hot take) all of my funding and training (minus steel training, cause Kelsier) cards. At the end, I have like, 8-9 cards that I use to kill the lord ruler in very few goes.
2. 2 Player. I believe, that at least in co-op, 2 players is the ideal. 1 player is *technically* better, but you can't specialize nearly as much. 3 players is redundant, I feel like that just gets you more time for the lord ruler to attack, and you have one person basically doing nothing. 4 players is the same, but worse (also I only have 2 people that I play this game with (my dad and my friend) and they are never in the same room together and single player is lonely so i might be a bit biased)
3. It's okay to bend the rules a bit. Sometimes, you just don't want to randomize those players, or mission track cards. Sometimes you want to play a game with very specific mission tack cards and characters. And that's perfectly fine. I mean, you shouldn't change any game play (i play insta-kill everyone!) but some minor set-up changes can make it a lot more fun!
What else do people do?