I've painted quite a few. Mainly for myself, but also some frames and helmets for friends and family. Check out my Instagram link down there ⌄⌄ for some photos if you're interested.
Frame is frame lol. They're all the same thing when it comes to painting, even material choice doesn't make much of a difference if you take the time to prep. It's not difficult, just very time consuming. I ordered mine raw and it really cuts down on prep time. There's tons of great stuff on YouTube detailing frame prep and paint techniques from people who are much better than me. If you've never painted before, buy some speed shapes or some kind of round tubes and practice first to get the technique down.
Here's a couple quick shots.