A lot of beginner piano technique problems can be fixed by a one simple thing.
How you sit.
There are all kinds of ways to sit wrong at the piano.
Feet dangling without something to place them on. (This applies to young children, or abnormally short adults.)
You think it wouldn't make that big a difference. But it does. It's one of those foundation things.
So what about you? Even if you're not a musician reading this (yet). What are some things that give you aches, pains, or challenges?
Do you need to practice more?
Or do you just need to double check the basics first?