There are some tips for general tower runs. It helps to know what the opponent uses This list
right here is incredibly useful for knowing the exact movesets. As a rule in Battle Tower you need 100% accuracy. In laddering and some tournaments you can afford to miss a rock slide here and there but one loss in the tower and it's back to the bottom.
Look at some of the gen4/5 teams as well (for some reason we never had a gen 3 records thread during that time, or I can't find it). Most strategies intend to exploit an AI pattern so it's impossible to not set up and sweet. Because the AI will get Quick Claw OHKO moves once you get high enough and that is really what you need to prepare for.