For my friend's birthday she wanted a gift voucher but I couldn't help but make something for her :D I wrote a haiku and copied it onto the mug.
Inside I put the gift voucher a couple of teabags and some biscuits.
the haiku reads:
One thin wisp of steam
and all my cares fade away
drowned in my teacup
Preheat the oven at 300 degrees Fahrenheit. (150 degrees Celcius)
Draw a picture or write a nice sentiment onto your mug and let dry.
Once dry, bake it for 35 minutes and take it out of the oven. IT IS VERY VERY HOT!!! let it cool down at least 30 minutes, the design fixes this way.
(if you can still wipe it off, bake it again)