Well, I like whites and light colors on guys in the summer such as pastels. Tanks are good and tees as long as you don't look like a store billboard with labels such as "HCO" or "American Eagler87." Witty tees are always good. :P
Linen fabrics are great. Try to stay away from heavy materials like suede or leather.
Really whatever you're comfortable in should be fine as long as you dress yourself properly, make sure everything fits.
Please no baggy tees or pants.
Pretty much anything from the following should suffice... :]