Writing with crayons can help their fine motor skills and also teach students control. Since crayons write a bit “fatter”, they’ll have to be more aware of their writing space.
Skinny markers are probably my favorite to let students use. They glide on the paper, are consistent, write small and exact like a pencil, yet add a fun pop of color!
You’ll be surprised how many students will pick pens to write with. I think they feel like a grown-up using a pen.