first just take a plain white shirt clean and ironed.

then draw finn and jake. Finn saying im on a t-shirt and jake saying me too!

Airbrush jake dark yellow with light yellow hilights and finns shirt light blue and his pants dark blue with very dim red hilights.

pic a backround color for the front and draw finns soword on the back abouve that write Adenture on the top of his sword and time on the bottom.