Every time anyone asks about writing tools, I recommend fountain pens. The fatter and heavier, the better.

Ballpoint pens absolutely murder my hands. I have to have a deathgrip on them to be able to press hard enough to make them write...it results in a lot of hyperextended fingers and hand cramps. Fountain pens write with little to no pressure so I can pretty much just prop them up with my hand and scoot them across the page without gripping very hard at all. Rollerballs are a good option too...the more liquidy ink in rollerballs seems to flow with less pressure than ballpoints. You can even get rollerballs that take fountain pen ink if you want to take advantage of some of the cool inks without using an actual fountain pen.

For anyone wanting to try an inexpensive fountain pen to see if you like it, I'd recommend the Platinum Preppy, Pilot Varsity/V-Pen, Faber-Castell Loom and Lamy Safari/Vista. TWSBI Eco is also good but can quickly become frustrating if you're the type that has to take everything apart to see how it works (though if you do run into this problem, there are lots of YouTube videos to help you put it back together correctly).

If I have to write with something really skinny, I grip the pen/pencil a little differently. Resting my pen between my index and middle fingers like this relieves some of the pressure on my index finger (the one that hyperextends the most). I'll do this even if I'm wearing my ring splints because my finger is so floppy the splints dig in uncomfortably when I try to grip something tiny.

For drawing and doodling with colored pencils, I'm finding that better brands marketed toward artists are easier to use. I used to buy whatever was cheap because I'm not a "real artist". Cheaper brands like Crayola seem waxier and feel like they need a lot more pressure to put down color evenly. Nicer pencils like Prismacolor feel softer and put down an even layer of color with less pressure. I wish I could find a cushioned grip that could quickly be transferred from one pencil to another to make drawing for longer periods of time more comfortable. If I try to put something on every single pencil then storage becomes a problem. If it's something that's going to take time of effort to put on/off then I probably won't use it. Maybe I can do something with kneaded erasers or Silly Putty or something...I have a couple globs of putty from PT sitting around somewhere. If I find something that works, hopefully it'll work on my drawing pens too.