I think the nail has been hit on the head already, good clean diet, low (to no) alcohol consumption, good protein straight after training and pleanty of sleep.
When you go to sleep at night and your body shuts down is when the majority of repair takes place and mentally you are ready to stress the body and learn new technique the next day.
Low sleep levels, alcohol, stress, poor diet all increase your body's cortisol levels and makes you tired, slow, weak, increases weight gain, lots of studies done to prove this and lots of fighters living clean lifestyles are breaking previous performance barriers and personal bests.
Remember with supplements that they are marketed to make you believe that you need them to be better, I can only comment from my experience of taking different things trying to increase my performance and recovery but the best thing i ever did was read a book called "The Palaeo Diet For Athaletes" (reading in general will relax you anyway but if its on nurtitional subjuects you kill two birds with one stone!), I also sleep a lot more, drink a lot less, and eat very cleanly ( which means for me no processed foods, breads, pasta, potatoes - lots of organic fruit, veg, meat).
The best thing to do is experiment yourself and find what works for you but I would personally try to not spend money on supplents (other than good protien shakes,cod liver oil, glucosamine,cherry active - basically natural stuff) before you try just improving the bsics first of your diet, sleep, stress levels ect as you may find that you spent a lot of money without any gains.
Hope this helps