The Dice-O-Lantern was created in Photoshop using just a small pile of dice as starter.
To duplicate the dice, I used the stamp tool, and created two layers, the front and the back.
The path tool was used to follow dice edges to form the eyes, note and mouth.
Shading does most of the work of making it look round. to do this, I masked out the outside edge of the pumpkin, then used the brush tool, set to airbrush, with very low flow to paint on shadow.
All of this was done with layers, so I could change any part as I went, or had to go back and make a change.
This shirt design is for sale here.