As duelist, weapon abilities like bleed and walking away, scimitar for more accuracy, quarterstaff for evasion, shield when you can’t avoid ranged attacks or ripper leaps, etc. Heavy Blow on hammer and hand axe make the enemies miss a lot. I’ll use these sorts of weapons as a secondary one and them some heavily upgraded weapon for damage. With Twin Upgrades on a champion, these weapon abilities last for many turns.

Other than that, never fighting more then one enemy at a time. Almost never getting hit by ranged enemies. But, yeah sometimes you’re just going to have to stand and wail on an enemy, and that’s where a +10 weapon wins. If you can kill them in 2-3 hits, you won’t take too much damage. Sometimes you get very unlucky RNG and miss a whole bunch of attacks in a row, but that’s what healing potions are for. If I run low, I make a Recycle spell and try to roll some more. Once in a while I need to.

Wand of Regrowth is amazing for blocking line of sight to ranged enemies, for instance, and rooting one enemy while you kill another. And you should make liberal use of your armor ability, whichever it is.

Oh, and most importantly, abuse surprise attacks whenever you can. Like, you can walk circles around a patch of grass, or a single-tile column, so that none of your own attacks miss, but the enemy can still miss.