How do I prep furniture before painting with chalk paint?

Krud Kutter works great for de-greasing

I always use a deglosser/liquid sandpaper. The brand really doesn't matter as long as you follow the instructions. If the item is really greasy, I would definitely use something like Krud Kutter, but if has just had general use, the deglosser gets rid of greasy fingerprints, etc. and makes the surface tacky which holds the paint better than a smooth surface.

after you clean it ; If it has shiny finish it needs to be prepped before using any kind of paint including chalk.....#1 furniture refinishing rule--" the shinier the finish the more prep work needed first" and the higher use the furniture gets the better the sealer( after chalk painting) needed like polyurethane instead of wax good info. http://www.vintagebarnboutique.com/2015/05/chalk-based-paint-myths-learn-how-to-paint-furniture/ sealing chalk paint https://www.youtube.com/watch?v=DnMTAh2c0e0

Before painting any furniture, I clean the piece with TSP and then wipe it off with a lint free cloth. The beauty of using chalk paint is that sanding isn't necessary.