Stay Active: After the game your adrenaline will still be pumping, take advantage of the energy and keep moving (go for a walk, etc.). If you crash on the couch right away, your muscles will get stiff, so best to stay active while you have the energy. If you are sore the next day, you should continue to be active with stretching, walk/jog, etc. The key to reduce the soreness is "movement".
Hydrate: before, during and after the game. Instead of Gatorade (or other "sport drinks" that can be loaded with sugar and other "stuff") try Coconut Water for natural hydration. Coconut water is high in electrolytes including potassium, which assures rapid hydration.
Increase Protein: Protein helps build and repair muscles. Increase your lean protein intake (milk, eggs, cottage cheese, chicken breast, protein shake, etc.) after the game.
Stretch and Massage: Yoga the day after a game feels SO good, and of course nothing beats a massage from Melting Touch! If you don't already have a foam roller, I HIGHLY recommend getting one. Foam rolling is a form of self massage - there are a ton of "how to" videos on YouTube if you've never used one. This is a very effective tool that will help with pulled quads, hamstrings, tight calves, etc. You should also roll before and after games to help lengthen tight muscles.
Epsom Salt Bath: helps reduce muscle soreness.
R.I.C.E (Rest, Ice, Compress, Elevate): If you've hurt yourself, ice the area as soon as you can. The ice will help reduce inflammation and offer some pain relief. Note: never exercise right after icing. Muscles should be warm before exercise.
Topical Aids: Tiger Balm, Biofreeze, Arnica, etc. These ointments can help to ease muscle aches and stiffness (Arnica will also help reduce bruising).