"Alright! We have the tools, we have the talent!" - Winston Zeddmore Ghostbusters

Step 1: Supplies

Dremel or Rotary tool
Extension flex tube attachment for Dremel
I used engraving bit 7144
Thick walled Mug or glass
Safety glasses
Permanent marker
Print out or picture to trace

Step 2: Trace

Place your image inside the mug. If needed trim it down to fit. If you need extra support you can add tape to hold it down. Trace the image or words on the front of your mug. Keep it simple so it's easier to work with.

Step 3: Etch!!!

I like to trace around my marker lines just in case I accidentally smudge the marker lines. It also helps to get you accustomed to the temperament of your glass with the Dremel. Fill in and have fun! I tend to lean towards "less is more."
When done, put mug on the top rack of your dishwasher to wash and your all set! Enjoy!