In reply to ldeight:
All this might have been covered in the other posts, but this is what I try to remember in order of importance. When on a 30 degree plus overhang, whenever possible:
1) Keep at least one foot on at all times
2) Keep your arms straight unless your making a move.
3) Its more important then ever to oppose static hand and foot (i.e. if moving your right hand you need your right foot on a strong placement)
3) Feet as high as you can get them without making yourself unstable, most importantly your dominant foot (in previous example your right).
4) If you can, drop the knee of your dominant leg (again the right in the earlier example). I.e. twist your leg so that your knee moves inline with your groin, your heal points away from your body and your hips rotate. Watch some footage on Youtube of Sharma on Jumbo Love and you'll soon see what I mean.
5) Once you've made a move bring your feet high as soon as possible. Often this can easily be done by simply matching your feet, but not always.
6) If climbing a short section of steep ground on a varied wall, look for good rests before you hit the overhang so you can shake out and suss the holds/moves/clips before you get there.
7) The hardest part of an overhang is often turning the lip, when you loose sight of your foot holds and your already shagg*ed. But your almost there so don't panic/give up!