Cook the rice and spread it on a tray to cool completely
Refrigerate the rice for at least 30 minutes, preferably several hours or overnight
Break up any clumps before cooking
Heat a wok or large skillet over high heat
Add oil and swirl to coat the pan
Add beaten eggs and scramble until just set, then remove
Add diced onion, garlic, and any other vegetables
Stir-fry until the vegetables are tender
Add the cold rice and break it apart with a spatula
Stir-fry the rice until heated through and lightly toasted
Add soy sauce, salt, pepper, and any seasonings you like
Return the eggs to the pan
Add cooked meat, shrimp, or tofu if desired
Toss everything together until evenly combined
Finish with chopped green onions or sesame oil if desired
Serve immediately