Oh man! I didn't even want to get in on the bands debate! I just wanted to show the different schools of thought.
Some guys say that the best thing to do is the lifts themselves. That nothing is as good as the classical lifts. And even if there was something that was "as good" it would be less efficient, because it wouldn't be the olympic lift. They talk about stuff like "dynamic correspondence" and "gradual progressive overload." Mastery of technique through practice and reptition.
Other guys believe that its more effective to get really strong and fast, and to build up movements that make up the olympic lifts. Like snatch grip pulls heavier than your snatch, and deficit work (or band work, or power versions of the lifts, or using pauses) requiring "more pop" than your snatch will build a bigger competition lift faster.