First of all ... bear in mind that I am old school ... and with my mindset comes a few do's and donts. It doesn't mean that I'm right and you are wrong. It's just the way I do things.
I train a single muscle group per day. I focus on high intensity training. In other words I try to exhaust the muscle as quickly as I can by focusing on forced reps aka (assisted reps), super sets and drop sets every other week with short rest periods between sets.
My aim is to leave the gym within 45 minutes and to get the biggest pump I can get within that time.
I need a partner to do this. Someone who can help me complete my rep when I'm shot.
I focus on three different exercises per muscle group and I do no less than 12 sets per session ... 3 x 4 sets.
Strength comes from going heavy ... and muscle comes from strength.
In the end it's about intensity and not quantity.