boiling point seems simple, it's also not that hard to mess up something like lasagna by overcooking it. And it's an excellent jumping off point if you want to use a slow cooker. Sautéing is similar. It's the basic skill that leads to stir-frying so you can work with more difficult recipes. And then there's baking. Baking things like casseroles helps you get familiar with your oven so you can cook food like roasted meats and chicken that require more advanced skills.
Once you get the basics down, you can try new techniques for more involved recipes. Outdoor cooking usually means you need to know a lot about your heat source and how it affects food. Indoors, braising is, for all intents and purposes, boiling food in your oven at a very low heat over a long period of time -- and getting it right takes practice, but it opens up a whole world of recipes to add to your repertoire like braised short ribs and braised kale.
Deep frying is typically left to advanced cooks because it's dangerous as well as difficult to get the results right when you're cooking at such high temperatures. There are great recipes to help home cooks learn how to do it, like donut holes or battered and fried vegetables. While sous vide makes cooking meat foolproof because it's more or less boiling meals in a bag, it's helpful to understand how heat affects food with other techniques before investing in new appliances.
You don't need a culinary arts degree from a French cooking school to be a master in your kitchen -- you just need the right recipes to help you learn cooking techniques and you can find them all on Yummly!