I get a lot of clients asking this question and it is a good question. Time is the primary commodity in the studio. Regardless of the rates studios charge, you're still spending your hard earned cash on time in the studio. The rate may be based on the gear the studio has or the experience of the engineer, but it still revolves around time. To make the most of your time in the studio, start with getting to the studio on time for your session.
The first step is to confirm your session a day in advance. Even if you confirmed weeks in advance, it's a good idea to send an email or call the studio just to confirm they still have you scheduled for a session. If for some reason the studio didn't put your session on the schedule, you should take a moment to make sure everything is going according to plan. Next thing is to call all the band members and remind them of the session. You don't want to show up to the studio and have to wait for your band mate to drive an hour to get to the studio. Carpooling is always a good idea.
Most studios will tell you when to arrive for the session. Some have a load in time and its always a good idea to ask if they allow time before the session for loading and setup. Either way, you should plan on being at the studio 15-20 minutes before the scheduled start time of your session. This will give you time to find parking and take care of any paperwork before your session starts.
Be sure to read my post about how to prepare for your studio session. This info will help you get the most out of your time in the studio. Please leave any comments if you have questions about this post.