jb90

Thanks for the great replies!
@Ramirez Could you tell me little about gear? Which bass did you record was the "easiest" and "great sounding" right after plug it direct? I have Musicman StingRays (those "after-EB" with 3band eq). Is that good and versatile enough bass to cover most of the scenarios or I must looking for other bass? I always want to know what bass guitar should have in terms of sound, etc. to give the best sound for engineers. You know... Just plug & play and there's not too much to do, don't need to use too much eq, compression or whatever. You know what I'm sayin. Thanks. 

How about a P bass...

@jb90 P bass is always popular, but generally I'd recommend taking a passive or at least an active with passive defeat. You can always add a preamp to a track later but you can't take one off once it's recorded!

Apart from that turn up on time, be polite, don't take any gear you don't know inside and out, and don't get in the way. If they give you dots then stick to them; if they ask you to keep to the vibe then don't overplay; if they ask you to go wild then feel free.

Session bass can be a shaky gig cause so many producers can play enough to get through a pop session holding down root notes by themselves, so you've got to be confident of your ability to bring something more than that to the table.