I think looking up synonyms is a completely valid way to figure out how to express yourself. they can be more than just replacing your thoughts with inserted words, their definitions can be tools of inspiration. thesauruses and dictionaries, physical or online, are great!
intentionally compare what you're trying to express to the definitions. I find this helps clarify and streamline thoughts through deduction, especially when a word isn't quite what you're looking for. you not only naturally gain a better understanding of what you are trying to express, but I often find other paths of interest.
even when I find a word or phrase that resonates, I still continue to search through similar ones, explaining to myself why this specific word fills what others can't. example sentences in dictionaries are a great place for the context of words too!
when writing, or even in conversation, I'll just search "another word for [insert my own word or phrase]".
I think this whole process of searching, reading, and understanding helps those words and phrases stick with you, as you've created like, a whole I Spy process out of it. I also just love rewriting definitions in my own words.