I hate pre-sanding and have gone way out of my way to to find a great way not to have to do it! It's all about the primer. Gripper. I don't care what you're painting or how shiny the surface, if you start with a light layer or two of Gripper, you can paint it.
This piece came from my husbands Grandmother's house. The glass had been long before we got it, but for my purposes it wasn't a problem. I needed it as a shove spot more than anything (I can never have enough of those......so many craft things).
The TUTORIAL on PAINTING WITH SANDING goes like this......
Coat 1: Gripper by Glidden. Don't go back over your strokes, maybe even thin it out slightly. It won't be a pretty coat.
Coat 2: zinsser primer/sealer/stain killer. Although gripper has some stain blocking abilities, the Zinsser does even more.
Coat 3: The top coat is Valspar multipurpose primer. I like this combo for the furniture because it's not gloss but it's also not too flat.
I hope you give it a try and share if you do.