After being tortured by seeing all the "diy plates" with sharpies, I feel honor bound to post that you really should be using a Pebeo Porcelaine 150 pen. Seriously, this is what we use and sell at work-- don't use sharpies people!
Make this cute hot chocolate mugs using porcelain pens.
porcelain pen designs
DIY Cross stitch monogram mug using porcelain pen
DIY Hand Painted Chevron Mugs
Black Porcelain Pen on white cups and saucers. Fun.
Handmålad kopp och fat – Handpainted cup and saucer
design ideas for my new porcelain paint pen (thanks @Emerson McAfee !)
Alisa Burke - porcelain pen decorating