Don't track guitars with reverb.
unless you're really ready to commit to the sound...
...also if you may need to punch in later...you won't be able to.
If you have not done so before, practice montoring with earplugs/headphones while you play. Takes some getting used to.
Big thing is have your arrangements done and well practiced.
GET AN ENGINEER TO MIX THE CD!!!!!!! DO NOT THINK YOU CAN DO IT YOURSELF!!!!!! GET THE BEST YOU CAN AFFORD!!!!!!!!
Tighten up arrangements before you get in the studio. No 8 minute pop songs!
Don't track guitars with reverb.
Don't be your own producers.