If you want a musical event to be better, make pertinent preparations. You probably have 2-5 hours to get ready. You may have less.
Look at the big picture. Are your clothes ready? Is your gear good? Do you know where you are going? Could you use a nap? Some food? What is your body telling you? Are your non-musical items squared away?
Once you have the logistics settled, maybe take some time to consider musical possibilities.
Identify areas that could use some attention. Are there many fast songs? Slow songs? Complicated forms? Songs you would like know a little better?
Decide the order of importance for your practice time.
Now get to it! Remember to include basic elements in your practice. Is your body warmed up? Are your ears warmed up? Hows your time and intonation?
Take time to relax before a gig, if possible. It allows your body and mind to store up energy reserves that you can use while playing.
Best wishes, tell a good story and send out the good vibes!