The playgroup I belong to, did a Make Your Own Travel Mug playdate. The organizer bought the travel mugs from Dollar Tree, and we were able to decorate them however we liked (the ideas are endless!). Here is my version:
The travel mug comes with a piece of paper that they can color to place in the mug, I used this as a template for designing my own instead. On one side I did a glitter handprint by tracing my son's hand and filling in the area with glue. Then, I just sprinkled glitter over the glue area.