The clock starts running whether your there or not. Make the studio a comfortable and relaxed place. If it's not it will show in your finished product. Before booking your studio time, ask to hear other material the engineer recorded. This should simplify the mix and eliminate the need for bouncing tracks later.
Surprises can cause problems.
The Recording Process Remember that it's emotion and feeling that make the best song, not necessarily the best technical rendition. If you mess up a part while recording, don't stop and start over. That can easily cause you to burn out. Instead, have the engineer punch in the correction. You don't have to fill all the tracks on the tape, don't try to force something that won't fit.