Combat options. I like them. I like simple tweaks. If you use two hands on a single handed weapon you get +1 to damage. Common sense dictates though, if a player tries to do this with a dagger a GM is indeed permitted to embed a 4-side in the requesting player's forehead. (The main reason I carry extra on me.) I like to keep them simple though. I don't want to calculate the arch of an arrow as it leaves a welsh longbow. Here are some simple rules I like. Please add some one you use to spice up the game a bit.
+1 to damage when two hands are used on a single handed weapon
+2 to hit for rear attacks, and the defender cannot use dex bonus or shield for AC
-4 to hit invisible opponents if you know the general location
-10 to hit invisible opponents if you don't know the general location
+2 to hit stunned, prone of motionless opponents and defender cannot use dex bonus for AC
Automatic hit for sleeping or held opponents
Two weapons, I am more of a fan of the -2/-4 to hit than +1 for 1 attack, but that would be something I would discuss with players and see what they like.
Critical hits, I like making my own table. The simple way we do it though is max damage and then roll normal damage on top of it. Sometimes I like the random effects of a good hit.
That's all for now. Lunch is over and I gotta run.