Step 1: Grab a ceramic mug. This particular one was left at my house after a visit from some friends (thanks, guys!) But, you can get some from any dollar store/Wal-Mart/Grandma's cabinet.
Step 2: A lot of websites claim Sharpies will do the trick. I've used both and ceramic paint pens have lasted through many dish washings. Sharpies can scratch easily and eventually wash off completely. I bought this pen at Wal-Mart for $3 and some change. (They have different color choices, but during the heating process, the colors fade slightly.)
Step 3: Draw/write your little heart out! I was inspired by this pin on Pinterest. It perfectly blends the nerd/gangster in me. If you're nervous about your artistic skills, don't worry! Mess ups can be washed off with a sponge (before baking.) I personally, love the imperfect handwriting/pictures. Learn to love your art!
Step 4: Place the mug in the center of your oven before heating it up. Because it's ceramic, you have to be careful switching from cold to hot too quickly. Unless you want cracked ceramic, (that's a whole other DIY.)
Step 5: Set the oven to 425 degrees (with the mug already inside.) Once it heats up, set the timer for 30 minutes.
Step 6: Leave in oven to cool completely (I usually crack the oven door open.) Run through the dish washer once and you're all set!
Tips: Practice writing on paper before you write on the mug.
For best results, use a ceramic paint pen.
Be careful with the paint pens, they can squirt out too much paint if you press down too hard.
Mug will be hot, hot, hot. Use an oven mit. (Duh, Lauren.)