I don’t have any tips that most don’t already know. I cook with simple ingredients. I save and freeze a bit of stock and cook with stock where I can. It adds a bit of depth that oil/butter doesn’t.
For my stock, I’ll save vegetable scraps and freeze it until I have enough. Then boil it down for a few hours. Vegetable is fun to play with. You can add different flavors, and different elements depending on the vegetables you use. Mushrooms will have a unique umami.
Same with seafood stock, I’ll save shrimp shells and fish heads and boil (simmer?) it down. Chicken stock I just boil the bones down after I roast a chicken. For beef, same thing, I’ll roast the bones for more flavor and boil it down. Also I’ll add carrots and celery to the boil for more flavor.
In a similar thought, I love to use coconut oil when cooking when I want a sweeter taste. And finishing a dish with some sesame oil can add a really good flavor. (Sometimes I’ll lightly toss noodles in sesame oil after they’re cooked, or do the same with roasted veggies)