Bad textures

I cannot for the love of llama figure out why I apply decent looking textures to a mesh and get something really weird in the end, one of simple examples being:


I am obviously doing something wrong then, but I have no idea what: does the material of the clothing matter, or is it something to do with bump/specular maps, or is it a some sort of stupid photoshop mistake I make? This read triangle is by far the worst I had to deal with