Pour some oil in a frying pan along with a small spoonful of garlic. I usually use olive oil for everything but that's expensive and has no benefit here so I just use whatever cheap oil I have lying arround for this, also you could chop your own garlic, but that's more work than it's worth in a lot of cases so do yourself a favor and buy one of those bottles of it.
Swirl the garlic arround the oil until you think the flavor has gotten into the oil, you don't want to roast your garlic so don't do this for too long. Once you're satisfied with that dump your leftover rice in, break the clumps apart and occasionslly stir it around until it is all warm but not crisp. Then dump that onto a plate and you've got yourself leftover rice that tastes better than any rice you put in a microwave and a hot frying pan ready for you to cook sometihng else in. Enjoy.