Party: Focus on high damage melee fighters, they are harder to get singled out and are easier to heal. Assassin provides stun, Brutalizer inflicts bleed for some extra damage, Berserker just does more damage, and Vanguard draws the aggro

Hero: Cleric is the safest as it has the most essence, Paladin provides a healing aura giving some decent passive heal to everyone near, working incredibly well with melee fighters. Necromancer has a damage ability making fights faster, but also has very low essence and no mana potion, making it the riskiest option

Spells: Healing Blunderbuss and Healing Machinegun provide the best healing rates, enrage increases crit chance providing some more damage

Equipment: Limit Breaker grants damage for life, Milk of the Muscle gives more damage on the first hit, Mark of the Death God increases damage taken on the target, Brass Knuckles can provide stun, and Dedly Dragon can provide insta kill if the target is under the threshold

Room Skips: By hugging walls you skip rooms and fights. Works best in the Dungeon and Sewer. If done optimally enough with a good layout you can even skip bosses