Everyone's a little different. For me before a ranked match I've partied and gone out the night before and played really well. Generally you'd want to be coming off at least 9 hrs of sleep but no more than 10 (I get sluggish). Tried pasta before matches but for me I feel like a sloth when I eat that stuff so I just eat whatever I'm feeling (nothing too heavy, no mcdonalds lol) and usually play great. Drink a lot of water and stay warm throughout the day. I like to do some light workouts before I play. I pack my bag with a lot of water bottles, energy drinks (like endurox or something else), energy gels if you are playing a long tourny, pretzels, random crackers, some choclate, change of shirt, general tennis stuff (wristbands, socks, hats, etc). Anything else you can think of that you may need.
It is not the mountain we conquer but ourselves.