The best things you can do to make your project the best it can be:
It’s about the song and the performance.
Rehearse the songs so you’re ready to record.
Record the songs yourself — using anything you can get your hands on and listen back. You’ll hear the song differently when you’re listening back.
Get the gear in shape.
Have the guitars professionally set up. It’s cheap and makes a big difference.
Get new heads on the drums. Not as cheap, but makes a huge difference in your sound.
Check out the amps and effects. If there’s anything wrong it becomes much more apparent in the studio.
Don’t use new gear on recording sessions. Use gear you’re familiar with, or you’ll be spending studio time figuring out your gear, which you should do ahead of time.
Take CDs with you.
Take the CDs you know and love to the studio for the sessions. It will help the engineer get what you’re looking for. It also helps you get tuned in to the sound of the studio, too.
Who’s producing the project.
Most independent projects are self-produced. Even if the project is going to be co-produced by the band members, there should be one person in charge to make the decisions in the studio. Too many cooks...
Closed sessions will get the best results.
Guests in the studio may seem like a fun thing but will only distract musicians and engineers. Plan other listening sessions either at the studio, or in rehearsal spaces to include other people if you want to keep them involved. It's hard to pay close attention in a busy control room. You'll find stuff later and wonder how the heck that got by you.