When I was down in Bournemouth doing some video tutorials for Hobbycraft, I made one of these t-shirts using a stencil and spray dye paints.
The one I made was with a spiral shape rather than the letters, here is the video...
If you would like to make one, I have prepared a step-by-step photo tutorial.
So.... grab a t-shirt and pop some cardboard in-between the front and the back to save the dye soaking through and marking the back.
Get some vinyl - this one is leftover Fablon from another project, but you could use masking tape, Duck Tape, anything sticky.
Cut out your chosen letters and stick them to the t-shirt.
For the dye I used this fabulous spray paints from Tulip. They work really well.
Give them a shake..
... and start to spray in small patches - you can always add more but you can't take it off, so start small and build up to the colour you want.
Add other colours.
Until you are happy with your design.
Now leave to dry for 4 hours before removing the letters.
Wash as instructed on the packet and Voilà!
You have a funky, unique t-shirt. Just for you.