Visualize!  With any personality, you can greatly benefit from having a basic pre-determined plan for playing each hole.   Start with the idea of managing each hole backward.  Choose a quadrant of the green you would most like to hit in to for various pin placements, then look back to the target you would like to hit from and determine which club you would ideally use, and so on until you are back to the tee.  It is mentally much more efficient to adjust a preplan than to create one  as you go, or to simply try to hit the ball as far as you can then decide what comes next.  Sound familiar?

Wake up!  Many players go into competition with an attitude that is not conducive to playing their best golf.  Some are too focused on outcome or results, some have a lot of self-doubt and negative self talk and some just wake up in cranky mood!  If left unchecked this attitude goes into competition with you and is sure to facilitate an unnecessary loss of strokes and confidence.  Simply set your alarm a few minutes early then before you even get out of bed, lie still, relax and imagine how you want to think and feel that day.  Try to, for example, imagine yourself calm, confident, patient, positive, walking and talking with confidence, decisive, committed to your game plan, carefree between shots, choosing definite targets, swinging with great tempo, etc.   Then mentally take yourself to the first tee and imagine playing your first tee shot with this great attitude.  If you have one, it can be a great help to recall thoughts, feelings and attitudes during one of your more recent great rounds,  just like you would recall shots to hit yardages.

Eat and drink to be merry!  No matter what time you are scheduled to play, try to have a meal balanced with protein, carbohydrates and fats within two hours of your tee time.  Carry nutritious and balanced, slow-to-perish snacks in your bag and munch on them at least every two hours. Unknowingly, many golfers wait until they are feeling thirsty to drink and by this time they can already be experiencing mild effects of dehydration, such as reacting to poor shots, finding it more difficult to make or commit to decisions, feeling impatient,  finding it more difficult to concentrate, or experiencing a sudden drop in performance.  I recommend that you make it a habit to try to drink on average one cup of water per hole. When its over 80 degrees every 15 mins.  Skip the sugary soda's cause its better to sip at the water fountain than to gulp a soda!