As I find them, I’ll share them. My two favorite cooking tips that I use all the time are:
1. Wine. Even if you don’t drink it, I suggest having a bottle of wine around to use while cooking. My favorite is an inexpensive bottle of port. (But I’ve used boxed wines and white wines) I add it mostly to anything sautéed and to meat while it is cooking. It brings a very gourmet flavor to the dish. (And if you add it in the beginning, all the alcohol gets cooked out).
2. Sugar (or honey or agave). I always add sugar to anything with tomatoes (or similarly acidic). It cuts that distinct tangy sensation and brings out the flavors.