Take all doors and drawers out.
Remove all hardware and hinges as well. Place hardware in a bag and label it.
Lightly scuff the surface of your bathroom cabinets with 220-grit sandpaper.
Use deglosser on a rag and wipe down all surfaces getting painted.
Use painter's tape to tape spots that you do not want to get painted. Consider spots such as a long wall, around the drawers and inside the bathroom vanity.
Begin using a primer with a brush and a small foam roller. Pay attention to cleaning up any drips. Let primer completely dry.
Clean your paintbrush.
Once the primer is dry, use a latex enamel in the color of your choice to paint. Use a brush for hard-to-reach spots and a small roller for the rest.
Let the paint dry and repeat for at least two coats of paint.
Remove painter's tape.
Let the paint cure as long as possible before putting cabinets doors and drawers back in.
Add cabinet protectors inside the doors and drawers to help eliminate extra banging when they close.