Make your own tshirts
All you need is a nice graphic and some tesco tshirt transfer paper. I opted for a white tshirt from h&m retailing at 2.99. It was slightly better quality than the asda equivalent for 99p.
I found a simple banksy stencil on flickr and cleaned it up a bit in photoshop to make it monochrome.
Then got the iron out and ironed it on. The life of these tshirts are usually like 6 months.
So next time you need a new tshirt make your own design rather than getting one everyone else has!