So firstly decide what design you want to have on your t - shirt.
There are some techniques :
But I did different way ,which I saw on youtube or in some blog (Haah,I don't remember :D) . Tie knots in the T-shirt and secure it with rubber bands. I tied knots like this .
Yep,this is picture of other t - shirts ,because I forgot to take one before dyeing them ,but tecnique is the same. When you tie knots in the centre of t - shirts , try to tie the same "towers" in other places. Remember - more knots - better ornament.
When tie enough knots , tie all t - shirt ,that they could fit in your hand. After that prepare clothing paints (follow instruction on packet). Put t -shirt in water with prepared paints and let it soak for about 30 minutes.
Than undo knots and rinse shirt in cold water. This is my result!