For sure you should rest the day before, don't do anything too intensive. Get plenty of sleep and eat right.
alot of rest & to be relax, like go to watch movie & go out with friends. But dont forget also to do the light badminton training. Playing with ball on the net, hit shuttle against the wall , improving drop shot, etc.... and the most important JOGGING, because it can help you to carry your stamina & they are all far from injury accident. So you will be better prepare for 1 tournament to the next tournaments
I'm a beginner at badminton, but experienced in sports. I suspect that with most physical competition, what you should do is stock up on carbohydrates like pasta and potatoes for 3 days before the competition, but not too much on the day of the competition. Eat breakfast on the day, and pack some snacks like energy bars and fruit. Oh, also prepare yourself mentally I guess, that will most likekly help. And, drink lots of water, like the carbs, you want to stock up on this for 2 days before, and don't drink too much while you are actually in a game, or between sets.
