if you have big hands and you're using a small-ish mouse a lot and your hands/wrist hurts, i really recommend getting a bigger mouse. it has seriously made a big difference for me
I just purhcased a (large) vertical mouse and it has immediately Changed Everything and I can never go back. Wrist pain ABOLISHED.
we have a left handed vertical mouse, so as to put the strain on the hand we haven't damaged as much yet
(we also have a right-handed one, but we don't use it, although one friend with RSI did point out that there is no reason we can't have both plugged in at once)
ergonomics is a very individual thing, don't just buy fancy products, think about where your stuff hurts and what position you'd like to be in, and then buy the product that lets you be in that position. learning to feel where the pain comes from is half the challenge
but yeah! vertical mice are great. not using tiny mouse is also great. repetitive stress injury is the characteristic work-related injury for programmers and many other knowledge workers, and as workers we all need to talk about it more. we strongly encourage people to pay attention to it when you're young. we can still feel every bad decision we've ever made about posture, they just... stuck with us.......
as someone who used a laptop on her upper torso, with no external keyboard, while lying down, throughout college and then got carpal tunnel, it's never too early to start actually trying to be ergonomic