A good thing to do is to go to shows, whether crowded or sparesly attended, and study why one band might go over well while another might not.
Ultimately it is the music, but performance matters too.
Realize that from the stage it might be disheartening to look out and see a big room with only 15 people in it, but from the crowd they don't see an empty bar - they see a full stage and expect to be rocked no matter what.
Also, practice what you'll play. In the case of performance, that inlcudes your moves. Outright choreography will come out as pure mouldy cheese, as will any contrived moves, but if in practice you let the emotion come out of you musically and physically, and by doing so develop a pool of physical expressions you can draw from, then it's that much easier on stage.
Ultimately it is the music, but performance matters too.
Realize that from the stage it might be disheartening to look out and see a big room with only 15 people in it, but from the crowd they don't see an empty bar - they see a full stage and expect to be rocked no matter what.
Also, practice what you'll play. In the case of performance, that inlcudes your moves. Outright choreography will come out as pure mouldy cheese, as will any contrived moves, but if in practice you let the emotion come out of you musically and physically, and by doing so develop a pool of physical expressions you can draw from, then it's that much easier on stage.