This tip I learned from experience. It deals with the difference of playing a guitar when your either standing up or sitting down. Like many people I prefer to sit down when I practice. This is much more comfortable for me and I seem to play better when I'm sitting. But, if you're a performing guitarist - especially in a band where you stand up when you play, I've found that you'll get much more out of your practice sessions if you practice how you're going to play.

To me anyway, eveything changes when I go from sitting to standing up. It feels different, the guitar is farther away from you and you're looking at your guitar from a much different angle.

The tip that I'm leaving for all you perfoming guitarists is "Practice how you're going to perform" This has really helped me and hopefully it will help some of you struggling with the same problem.