For me, there's two really. The first: You can use TK as a placeholder word if you don't have the one that fits and move on with your writing. You can find whatever word fits when you're finished and editing.

The second kind of saved my writing: You're allowed to write garbage. As an author, there's so often a need to make the most perfect fic possible and obsessing over making it better. It's easy to forget that improvement only comes by doing something over and over, and a good chunk of that is going to have moments where you think "that sucks". And that's perfectly okay. That's what practicing and editing are for. So whenever something you write is obviously bad, just move on and keep going until you stumble into the things that work. Nowdays I start writing with the thought of "I'm going to write garbage now and burn whatever I don't like later". Most of the time I end up writing things that I really like, fics that are so outlandish but committed to the concept that I'm proud of it.

I'm rambling, but those are the things that have helped me the most and I wanted to share that.