Above is my Zeus rash guard which would be used for MMA, Brazilian Jiu Jitsu, Muay Thai, and other combat sports and physical exercise activities.

Below is the beginning of my process where I created an illustration gradually increasing the size of the pencil thickness, till I got a final design I was happy with.

I then put these illustrated designs into Illustrator did the line work, made the rash guard, and coloured it all in.

After that I put the Illustrator document into Photoshop where I put a colour overlay over the top and added a glow to all the lightning and Zeus's eyes.