GO left because everyone is going right. It is a truth that people tend to go to right when given a choice (watch people and you will see this is true).
This means when you enter a park go LEFT NOT RIGHT to maximize your time. A great example is for Magic Kingdom.
An example of this is last time I was there, I rode 6 rides (times) by noon, using only an 1150-1250 Fastpass. Yes, you can do even better than that as well.
Use your Fastpasses for the rides that are right. Maximize time, maximize fun.