| I do roughly 10 -12 sessions a year, usually rootsy Country, Blues, 'n' Rock'n'Roll recordings for singer/songwriters and mainly at a couple of local demo studios, with the (very) occasional "pro" studio date, so I'm far from a full-time session pro. But here's my advice anyway, FWIW.
*DON'T* charge by the song or you'll get caught by the Steely Dan wannabe who takes 3 days just to get the first verse right. This is only a slight exaggeration. A Guitarist buddy of mine used to charge by the song; he learned the hard way when one guy took EIGHT FREAKIN' HOURS to get a three chord Country song into usable form...
I charge a couple of hundred bucks for a standard three hour session and I'll usually get through three, maybe four tracks in a three hour session. This is assuming everyone else has their crap together and it's ready to go when I walk in. I only take my Bass(es) and a tuner and lead to sessions. I'll always take my SansAmp Bass Driver as well, "just in case".
But I'm not a total clock-watcher - if a track's nearly done, and the client hasn't been a total butthead, I don't mind doing an extra 15 - 30 minutes.
__________________
Phatbass - Bassists with Beards Club member no. 26
"You say heroin-addicted bisexual Satan worshiper as if it's a BAD thing"
| 
