When you play try to pay more attention to open strings that ring out when they are not supposed to and finger noise when sliding to different positions. I noticed this problem midway through my first CD when it was too late to do anything about it. With a little practice you can perfect your palm muting and even muting adjacent strings with your fret hand as well. Practicing with out effects is important because most engineers will want to try different things before committing to one effect right from the start and will ask that you don't use any effects other than distortion during the tracking process. It doesn't take much to get used to it, but you again will hear every little bit of string noise and mistakes will be more obvious with out reverb and delay.
Technique is everything.
It is also very important to know your material before you go into the studio. Save your solos for another track. I didn't know that guitar solos usually went on a separate track and had an engineer stop the tape and ask me what the hell I was doing when I went into the guitar solo instead of staying with the rhythm part. I was caught of guard because I had never played rhythm there and had to get the other guitar player to show me what he played in that part of the song which cost us some time because I needed to learn it before I could play it. You may also be asked to double tracks, or even to play something in the background to accent a part that the producer thinks needs to stand out more.