Upper Body: For me, I always do a warm-up set 15 reps average with approx. 70% of my current maximum "working set" weight, then working up to the max. weights which I'll do about 3 sets of 10 reps with. After this, depending on energy level- I'll do "descending sets" using 5lb less each time (or 10lb IF I'm in a hurry) and just burn the muscle group until you could literally melt butter on it... always striving for at least 8 to 10 reps on each set!!
Lower Body: For Quads, Hams, Calves, a warm up set again with 70% of max, this time doing 20 reps, increasing weight each set keeping 15 reps as an average. 2 to 3 sets of 15 reps with MAX WEIGHT as the "Working Sets". NO DESCENDING SETS for lower body, the weights being much heavier than upper body sufficient for stimulation.
*** Exception to all this is ABS, I prefer sets of 50 reps, 5 to 7 sets- 2 different exercises SUPER-SETTED.