Each body part once a week, spread out over 4 training days seems to work for me. (Like 4 sets of each exercise, approx 8 reps).
Mixing up rep schemes on occasion as well. Everyone's different. I've tried other methods (5/3/1, Bill Starr 5x5, etc).
Maybe I just enjoy my 4-day, 4x8 the best (not big on change)... Find what works, good luck...