While most of my work over the years has been straight illustration, either for books or games, ocassionally I am asked to work on a project with more of an emphasis on design.  The following are samples from my portfolio of projects meant specifically for t-shirts.
Project: "Orgullo de Mexico"
Art director: Jim Pinto
Description: This project was for a proposed t-shirt design for Jose Cuervo tequila.  The design was to be screenprinted, so we were only looking for a single color design.  I was asked to feature the bottle prominently, as well as the historical figures of Pancho Villa and Eufenio Zapata.  This is the rough draft.  As often gappens, the rough has quite a lot more life than the final piece, so I've included it here.
Here is the final art for the proposed Jose Cuervo t-shirt design.
Project: "Sparksism"
Client:  DJ J-Sparks
Description:  The client had a hand drawn design that he wished me to improve.  I was able to redraw and re-layout the logo so it had a bit more flair.
Project: "Fear the Frog"
Client: DCST Dale City Frogs
Description:  The swim team often sells team merchandise as a fundraiser.  I donated these designs for their use, incorporating the team motto "fear the frog".