how do i shrink a t-shirt?

[freshfruit]

as above, got a free t-shirt yesterday in a buy1 get1 free deal. It's a large and i'm a small-medium, bearing in mind i'm really not bothered if i wreck the free one, can anyone suggest the best way to shrink it a bit? Its cotton, cheers

[FP]

Wash it in the boil wash in a washing machine and then tumble dry it. It should shrink. Wash it alone because the colour will run on a very hot wash.