Wow...where to start? Here's a few:
1. If you're casting plugs or "rapala"-type lures. (they gotta float) Once the lure hits the water, let it sit for 2-3 seconds and then give it a twitch and let it set for 1-2 more seconds before you start cranking. I've had many strikes come before I started cranking.

2. Watch the weather for cold fronts. Back home in the South, bass will often move into the to feed shallows 1-2 days before a cold front comes through.

3. If it's lightly raining, keep on fishing. The fish are already wet.

4. When buying lures, look at what's in stock over a couple of days. If the store offers a lure (worm, spinner bait etc.) in several colors & patterns. Don't get the ones they have the most of, unless they just re-stocked the shelves. Ask the clerk which colors & patterns they sell the most of, and get those.