Practice regularly without skipping one day. Long rehearsals are no substitute for daily practice.
Practice with one small goal or improvement in mind each day.
Isolate technical problems and work on a one- or two-measure passage.
Focus on the downbeat and upbeat where there are rhythm problems.
Work very slowly where there are fingering or pitch-change problems.
Memorize your musical presentation.
Get a CD of a professional performing your repertoire, if possible. Listen to this CD and incorporate any styles that you and your teacher feel are musical.
Improve your music memorization skill by humming or whistling the melodies when walking or traveling in your car.
Become thoroughly prepared. This builds confidence and helps you prepare for the recital.