This is one of those huge topics that you could write a whole book on (and people have), but I’ll start with my basic tip: pick a cooking method to complement the meat in question. There are a lot of different ways to cook different meats and they’re used for different reasons. The way you cook a steak sucks for brisket and cooking a steak like a brisket is just as bad. So think about the kind of meat you’re cooking and what you want to do with it.
Thin cuts, moderate fat, tender, like most steaks: These cuts just need some heat and flavor - you’re trying to preserve the basic moisture and texture. Cook as hot and as fast as you can. Use a grill, broiler or a really hot, dry pan. You want good char/carmelization on the outside, but without killing the interior (pink/red for beef).
Thin cuts, low-fat, tender, like most fish, pork chops and chicken breast: These cuts also don’t need a lot of help, except maybe to add moisture/fat. Consider pan frying, as this gets you a crispy outside and the oil helps to counter the lean meat. If not, practice the same basic practice as above, but keep in mind that leaner meats stick, so you’ll almost always need some oil to help.
Thin cuts with lots of connective tissue, like most flank steaks, and other less ideal beef steaks or end pork chops: You want to minimize the toughness caused by the connective tissue and avoid the tendency to dry out. Marinade, if possible, to start breakdown of the meat before cooking. Cook quickly and hot, like the first category of steaks. Counteract the connective tissue by cutting the meat after cooking into thin strips cut across the grain. Some people use tenderizers and frying techniques can still work well (chicken fried steak being an extreme example of both).
Thick cuts with lots of connective tissue, like pot roasts, pork shoulder, brisket, etc: Cutting is probably not realistic as a way to deal with connective tissue here and the thick cuts protect moisture. Cook slowly and for a long time. Consider smoking (say, 200 degree heat, lots of smoke, for 4+ hours), braising (cooking with liquid in the bottom of the pan), roasting/baking and other slower methods. Count on collagen and fat to keep the meat feeling moist to the mouth, even if it’s thoroughly well-done. Sauces don’t hurt either. For some cuts, you can start with a hot grill or pan to get the outside seared, and then finish slowly.
Obviously, this is largely simplified, but it seems to help a lot of people I talk to, who don’t realize the interplay between cooking methods and