Yes and no. It depends on the materials involved. Things like silicone toys can be made with minimal effort. Things made of wood or glass need a bit more skill and preparation. Things made of glass require a skilled artisan.
Yeah, as much as regular sex toys; I would think about the safety just as much. I would not try making sex toys that could get stuck too easily, though, especially those linked somewhere with a cord, for I suck at placing those things solidely.
I looked into some of the DIY sex toys. Some of them I just couldn't do. A lot of them were toys I get for my son. Too weird. Or they require a little too much work. Though, I'm curious to try the one of making my own little whip out of cheap bungee cords. I guess you strip the material off, and then tape it at the bottom. That's only one I'd try. There was one saying to use little traffic cones (that go on your desk) as a butt plug. Eh, I'm good. I'll stick to my designated plugs.