It depends on the material. Most synthetic fibers or even natural/synthetic blends are made nowadays to not shrink. If it is made out of a material that shrinks, there's always good ol' fashioned outdoor clothes lines. And if you think a simple t-shirt will shrink, try sticking a wool sweater in the dryer. It ends up being doll clothes! lol
be careful
you know what they say about the tekkie with the red shirt
(great look though)
T-Shirts shrink ALLOT..
Maybe it should be washed a few times first before modifying it.
...and hot!