These mugs are so simple to make, even if you aren't confident in your drawing skills you can write on the mugs. Maybe try writing song lyrics, quotes, or simple phrases like "keep calm and drink tea".
1. Making sure your cup is clean, doodle or write on your mug using your sharpie.
2. Set your oven to 350 and bake for 30 minutes.
3. Let them cool completely before using or washing.
I haven't tried running them through the dishwasher yet, so we'll see how they'll hold up.