Yeah that is a pretty vague question! Like optimum arousal is where performance is at its greatest! Also nutrition has a big part in enhancing performance e.g. carbohydrate loading for aerobic performance and even talk about supplementation like caffeine can aid performance in regards to glycogen sparing! However, as your question was very vague I just put a few possibilities that could enhance performance! I hope this is what you wanted!
There are physiological and psychological skills that can be applied to enhance performance as well as the nutrition and fluid intake and in everyone of those things i just mentioned there's more points coming off them..