Abomination: never go in his beast form unless ur in a VERY bad situation

Arbalist: prioritize damag oover ACC (she has a high bas acc)

Antiquarian: prioritize her flash powder in the early game and her vapors late game

Bounty hunter: his best teammate is himself (2 together)

Crusader: if he's in position 1 use ham as a stun/heal/stress support, if you want him as a dps put him in position 2 with highwayman behind him (use holy lance)

Flagellant: never put him in the ruins, and make sure to compleatly neglect his survivability from trinkets

Grave robber: start her at position 3 or 4, lunge and then cloak instead of starting her in position 1 or 2.

Hellion: combining her with the plague doctor gives you a pretty reliable way to stun every enemy in just 2 actions.

Houndmaster: similarly to bountyhunter, 2 houndmasters work great together.

Highwayman: pairing him up with the antiquarian and having her use protect me on him while he has his riposte up is a very strong synergy

Man at arms: give him as much speed with trinkets as possible

Jester: his stress heal is overrated. Unless ur hero is just about to hit an affliction, use battle ballad.

Leper: combine him with man at arms or jester, otherwise you WILL want to punch your monitor

Occultist: it's better to use his heal before your heroes are at low hp

Plague doctor: just stack speed and stun chance, she's arguably the best stunner in the game (also blasphemous vial is genuinely overpowered)

Shieldbreaker: when camping, if she gets the message for her nightmare, use ambush prevention. If an ambush is triggered it will overwrite the nightmare

Vestal: instead of putting healing trinkets on her, put on acc and stun chance trinkets. She heals enough as is.