I'm sure you're going to get a lot of specific random suggestions. Nothing wrong with those; I always keep a list of the ones I like.
I'm going to go general with my answer, though.
First, you guessed it, keep a list. Anytime you come across something cool online, or an idea pops into your head, or you walk by a building or a park in your town and think, "man, I could totally build something in that style in Minecraft", or whatever, write it down ASAP. Whenever I'm sure I'll remember, it's gone in five seconds.
Second, watch other survival players on YouTube (or maybe Twitch). There are many ways to play survival Minecraft, and you might need to explore some of those ways yourself to figure out what kind of player you're going to be (at least for now), but watching others' content is a good way to mainline a lot of playstyles in a short amount of time, for inspiration or "eww, that looks boring to me. Guess I can cross that off my list..." types of realizations.
Third, set goals. No, don't stop reading, this isn't as boring as it sounds. All I mean is, the quickest way to get bored and burned out playing Minecraft is to have nothing to do. You need goals. Every time you play, just pick two or three things (maybe from that fancy list you are keeping) that you want to try working on. It's 100% OK if you change your mind later. The important thing is to have something to work towards. Don't feel you need to finish everything in one sitting; in fact, having something specific to look forward to next time you play is one of the best things you can do, and that may as well have been a separate tip all of its own.
Finally, if you aren't having fun or you're not enjoying the grind, do something else. If you're tired of mining, try building. If building isn't going well, try a redstone project. If that gets creepered, light it up and then go exploring. You get the idea. If the game feels too much like work, you're going to lose interest a lot more quickly. Better to have an unfinished project (or ten) in your world, than to abandon the whole world/game altogether.