u/FuckYourMom has good tips.

I+G, disodium inosinate and disodium guanylate, have a synergistic effect with MSG. It is why processed and restaurant food can taste better than anything at home.

Also, make a good sear on meat. Char is delicious, the frond left behind is delicious. You want to deglaze your pans with beer/wine, broth, or even water and keep that flavor.

Sugar is the missing ingredient that makes people's fried rice at home not taste right. I hate adding sugar to things, but that's it.

Get away from using recipes if you really want to cook. A recipe is an instruction you follow, you're making someone else's dish, but when you know the why of what you're doing, you don't need them except for ideas or reference.

The spice most people skimp on is salt. Also, black pepper -- I fucking love it, but it doesn't need to be used at all really.

If you can't tell a good recipe from a bad recipe, get a cook book. I had a hard time making good Mexican food for years cause there's so many shitty recipes out there and I couldn't tell a good one from a bad one until I got Diane Kennedy's Essential Mexican Cuisine. My only cook book. Basically if you don't know how to cook regional food, you need a solid way to learn and not be waylaid by bad internet recipes.

I'll try to think of more, there's a ton.