Here's a quick list to help you be better prepared and save you time and money in the studio.

Guitarist and Bassists
Please have your guitars and basses setup by a professional prior to your session. It's relatively inexpensive , but it makes a tremendous difference.
Right now Riks Music is offering a special deal for all NightSong customers ! They will take an additional 10% off of all guitar work needed prior to your session.
   Intonation work and neck adjustments
   Guitar setups , fret dressing and more, leaving your guitar minty fresh !

Always change guitar and bass strings one day prior to your session to give them ample time to stretch. Don't forget to bring spare strings !!
Please have any electrical and/or ground hum problems fixed prior to your session.

Drummers
New drum heads and sticks
It's a chunk of change, but if you want the best tones from your kit, it's a must. If your on a limited budget, at least change the kick and snare heads. Don't forget to have a hole cut in your front bass drum head for mic placement.
A note on drum heads : I'm not a drummer, but I know what works in the studio. I prefer COATED heads for snare and toms, from Evans, Remo or Genera. They need less dampening, and for recording, they just sound better no matter what style of music your playing.
Bring plenty of fresh sticks too !!

Vocalists
If all possible, please supply us with a copy of all lyrics before your vocal session. It makes editing, punch-ins and corrections much easier to do.
Avoid smoke, alcohol, dairy products and screaming.... and screaming with a mouth full of dairy products ; )  prior to your vocal session. Throat lozenges and sprays are another big no no.
All Citrus items are a big plus ! Lemon juice, orange juice or just plenty of water is fine also. Hydration of the vocal chords is a key element.

Radio Friendly Material
Are you recording material for local radio airplay ? Then you may want to stick to some stricter guidelines.
1. Length : Keep your songs around 3:30 minutes. If it's over 4 minutes, your song will probably not see the airwaves anytime soon.
2. Content : If your lyrics have some " not so squeaky clean " words, bring us a lyric sheet and be prepared to do a radio edit mix for that song.

Other than that...practice, practice, eat some pizza then practice and I'll see you at the session !! ..............JJ