How do you choose your needle size?

Hello friends! I'm currently enjoying some Saturday afternoon stitching (yay!), which has included some digging through my needle stash. After some back and forth, I think I have officially decided that I prefer a size 24 needle over size 26 for 18 mesh canvas. I know this is the type of breaking news that you would appreciate. 😂

I tend to prefer smaller needles for detailed work, but my size 26 kept falling out of my canvas today, and it was driving me crazy. The size 24 is bulkier in my hand but doesn't fall out of the canvas... plus it's easier to thread.

This got me thinking about what size needles everyone prefers, since I know needle size can involve a lot of personal preference.

So what do you use for 13 and 18 mesh? Do you have a go-to size for each canvas type, or does it depend on how thick your thread is? Do you switch up your needle size on interlock vs mono canvas? And if you tend to switch it up often, what factors do you use to decide?