Well here's another tip:
When using photoshop, you may want to select all that yellow, copy it to a new layer and apply a layer effect to it by right-clicking on the layer and select the option (I have the Dutch version so I don't know what the English line says). Then go to the "Structure" option and select a structure that matches lines on a (T-)shirt. When I'm at home, I could post some pictures, but I hope you understand what I mean. It gives the T-shirt even more detail!