Darkheart:
First of all, I think it will be good if you change your subject title to something more relevant, like "How to improve my band's stage presentation?"
Back to the topic at hand...
First of all, the band has to sound tight enough. Drums and bass have to lay a solid foundation. No point having the band doing stage acrobats when the band doesn't sound tight.
Next, be comfortable on stage. Move around. Show like you are enjoying yourselves on stage. No one really likes to watch a band that stands still throughout a gig. Might as well go home listen to CDs right?
Watch videos of how top bands perform and learn. I don't mean copy, but learn how they look so comfortable on stage. Even better, video down yourselves then watch and review how you look when you play. Do you look like a block of wood concentrating only on your instrument, or do you look like you are grooving along to the music and having a good time?
Stage presence will come when you have got the above stuff done. Hope that helps