"Now if you are going to win any battle you have to do one thing. You have to make the mind run the body. Never let the body tell the mind what to do. The body will always give up. It is always tired morning, noon, and night. But the body is never tired if the mind is not tired. When you were younger the mind could make you dance all night, and the body was never tired...You've always got to make the mind take over and keep going."
If you're a novice/intermediate and are unsure what routine to follow: http://i.imgur.com/U4fK658.png?1?3081
Dealing with Lagging Body Parts: http://i.imgur.com/o7WgfKY.png?1
Greekmanman - "Using what the research suggests is most optimal for the majority of trainees as chances are you fall in line. After several months, gauge your progress. If you make better progress, great. If not, time to experiment with higher volumes, higher frequencies, etc."