My favorite super easy way to cook tofu is to dry fry. Cut into cubes, or fairly flat pieces. Drop into a ripping hot non-stick pan. Use very high heat, like 7 or 8 on my electric stove works for me. Important not to overcrowd. Depending on the size of your pan you may need to split into batches, but you want to drive off the moisture and get it slightly brown on all sides. Stir and check the browning frequently, should only need like five minutes or so to get all sides browned. Then add a tablespoon or so of your oil of choice, and cook for another minute or so and the sauce with whatever you like. Just soy sauce is perfectly good here, terryaki, storebought stir fry sauce. I really like a mixture of soy sauce, rice vinegar, sriracha, sesame oil, and maple syrup. Can adjust those proportions to taste, but be light on the sesame oil because it's very strong.

A lot of dry frying recipes call for pressing it or drying it with a towel, but I find that unnecessary with most firm or extra firm tofu.

This is now my normal way of making tofu to accompany a stir fry veg blend or just some steamed broccoli over rice, but it also works for sandwiches, wraps, etc. A lot of people like to marinate tofu and I used to, but I really like doing this because the texture you get by letting it cook and driving off the moisture before the sauce absorbs is really nice and you don't have to mess with prep beforehand.