Among the texture creation world, there is a feared and evil entity, which has already decimated thousands of maps, and which now I bring to you. Prepare to enter the dark and evil side of the PATTERN MAKER.
Now seriously, I’ll explain you how to use a tool, which is probably the fastest way to get textures directly from pictures, and it's a good solution to create organic materials.
NOTE: Photoshop 7.0+ needed, some steps may not be possible in older versions
First of all we will need an image, so I did a little google search and found this nice grass picture
Now open up you picture in Photoshop, and click two times over the background layer to unlock it. After doing this we are going to open the pattern maker either by going to the FILTER menu and then selecting the pattern maker, or by using the shortcut alt+shift+ctrl+x.
You will now see how easy it is to create a grass texture using this tool. You don't need to mess around with any settings, just going to say which ones i used here, this ones will for sure work in any type of texture:
Sample detail: 5
Tile Boundaries: unchecked
Select a good and interesting area from your picture, and make a square around it, and then press the GENERATE button, and after it generates you texture, press OK. This will bring you back to the Photoshop main area.
You have your texture ready, no need to make it tile, since the pattern maker, does that for you, Just need to resize, and tweak whatever you want, and there you have a grass texture made in 5 minutes.