Don’t save your viva prep for the day before your viva.
Save that day for reminding yourself of your successes.
Save that day for reinforcing that you’ve come as far as you have by becoming more talented, more knowledgeable, more capable.
Save that day for remembering that you couldn’t have produced your thesis by being lucky – you must be good.
Save that day for relaxing.
Last minute viva prep can be stressful. Save those last minutes for looking back and simply reflecting. Remember that you’re good.