tutorials?? well depends on what you are looking for.

the basic step is to create the dodge and bump of the fabric. You can use different techniques and filters for that. The most common one for a cutrain would be the gradient. Apply some noise to it and then either add motion blur to get a smooth looking fabric or a cloud renderer for a more caustic look.
Pick a color or patternlayer and overlay it witht he black and white gradient bumpmap. Then you can add further effects as needed to get the right look for wrinkles, stains, grain, structure or reflection. If you are good you can use the bumpmap as disortion map as well and can define a movement of the fabric. So the pattern wont be tiled from top to bottom but will follow the bumping like in real life. (you can also use the deform tool for that...just make sure you affect the colormap and the structure map at the same time)

see..no rocket science