I describe the monster's attack (A vicious overhead swing...) whether it hits (slams into your armor...) and then the damage (you take xx!). I let the players describe their attacks to me, though some just tell me what they rolled. If I get that I throw out some descriptions (Your arrows slam into a poorly armored part of <monster>, dealing him a staggering blow, he looks to be barely alive!) I try to avoid "okay, he rolled a 17 to hit, which beats your AC, so you take 32 damage, who's next?", it's just not as exciting. I also try to avoid the monsters having HP bars and discourage my players from saying things like "I've got 10 hp someone toss me a heal" unless we've moved out of combat, since then it's reasonable that whomever has the wand is doing a triage type setup and is gauging who is the most hurt.
I want my abstracted numbers to remain abstract dammit!