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!
How to print a saying and trace it onto your mug and then color it in.
DIY Cross stitch monogram mug using porcelain pen
Pébéo Porcelaine 150 cups and saucers http://www.dickblick.com/products/pebeo-porcelaine-150-paint-markers/?clickTracking=true http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps=Porcelaine+150+pen=i%3Aaps%2Ck%3APorcelaine+150+pen
Handmålad kopp och fat – Handpainted cup and saucer
Make this cute hot chocolate mugs using porcelain pens.
lots of gift ideas, i really am fond of the decorate a plate...might add a scrap of fabric, baked goodies and some pretty ribbon/lace/twine and call it a gift!
De jolies assiettes à realiser avec les feutres #Porcelaine150 de #Pébéo
Google Image Result for http://3.bp.blogspot.com/_wvcCE9jbIg0/TVCxAsc68AI/AAAAAAAAH18/dDhZfu84LgU/s400/step%252B6_wait%252B24%252Bhours%252Bthen%252Bbake%252Baccording%252Bto%252Bdirections.jpg
design ideas for my new porcelain paint pen (thanks @Emerson McAfee !)