Trimming is good. Shaving is good. I do some of both.
Not sure I have any advice on how to make it not painful; I've been shaving or trimming pretty consistently since I first got hair down there, because I found the itching intolerable and I hated it in association with all the other changes I was going through. It is easier when you stretch the skin tight. And don't use too much pressure. And use a high-quality women's razor, if you can stomach it; they're meant for bodies, so they have a broader surrounding surface that reduces the blade pressure against your skin, which seems to reduce cuts and increase comfort at the expense of just a little closeness.