The easiest way to quickly upgrade a bowl of instant noodles is with ingredients that require no extra cooking. I'm talking simple sauces and condiments like:
Chili bean sauce
Thai curry paste
Japanese curry powder
I'm a condiment hoarder (I've got a whole double-layered shelf of my fridge plus the entire door and a full pantry cabinet devoted to them), so this is a particularly easy thing for me to do. The key is not to go overboard with too many different competing flavors. I often make this mistake after long nights out, assuming that when it comes to hangover cures, more is better. Not the case. Keep it simple. Bear in mind that if you're using a salty condiment, you should omit some of the seasoning packet.
⁃You can also add:
Spices like white pepper, sichuan pepper, or chili flakes to the finished dish, or try adding a cinnamon stick, star anise, and coriander seeds to the simmering broth (remove 'em before serving!)
Fats like toasted sesame oil, chili oil, or an animal fat (pork, chicken, or duck are all awesome)
Citrus juices—a quick squeeze of lemon or lime right before serving can go a long way to brightening...