One of the things I see my son struggle with is holding a pencil properly. Now in almost any case this wouldn't bother me but you can tell he struggles to have control of what he is writing with. Not only does he struggle with control of where he draws or tries to write but also how hard he is using the pencil, crayon, or pen.
I was told about these through a homeschool store in a nearby town about these Grotto Grips. They were made by an occupational therapist and they're weird looking. If you go to occupational therapy long enough you'll see tons of weird shaped things that help you do normal every day tasks so I bought some. I got to try them before I lost them and they do work to keep your hand and fingers in the correct position so you do have good control.
Now I have go buy some more from either Amazon or the homeschool store because Staples and Office Depot don't carry them. (I posted two links for them from Amazon so you could see the product itself and then one with it being used.)