First off find some textures you'd like to use.

Here's some I found:

Superimpose:
1. Open a black or white background in superimpose. (Depending on if your textures are dark or light) add your first texture and place it where you'd like then go to mask and you the gradient masking tool to mask the edges like so. Merge.

2. Keep adding your textures to your liking when finished save your textures.

Now you have a texture for your Manips and all that lovely stuff! Hope you liked this tutorial I'll have more textures for you soon!!!