I'm not a bodybuilder, but my general rule of thumb is; 2 compounds and 1 isolation.
First compound is for strength - 1 set of 5 or less reps
Second compound is for muscle - 4 sets of 7-10
Then finish off with an isolation exercise to work on a weak point, balance, or just because it feels good.
Bench Press - 1 x 5
Db Bench Press - 4 x 7
Triceps Extension - 2 x 10