This tutorial will teach you how to make a seamless "mixey" background of abstract qualities in Photoshop.
I figured that nice seamless backgrounds can be a bit tricky
to make, and so I decided to throw together this simple tutorial on how
to make your own seamless background with a bit of a mixed feeling.
Make a new document. I generally find that 300px by 300px makes a nice size.
Stick with a size in which the height and width are the same.
Create a new layer.
Choose two colors: a foreground and a background color. Then, hold down
SHIFT and hit the BACKSPACE key in order to fill in the canvas with the
foreground color.
Filter>Render>Clouds (or Difference Clouds; do this until you have a nice
combo of colors).
You can now apply a filter or two to get a varied effect (Don't be too precise;
it'll just be for a slightly different, non-smooth or textured look in the
finished product). I'm using Filter>Distort>Ocean Ripple with Ripple size:
9 and Ripple Magnitude: 20.
Filter>Distort>Shear. Make sure "Wrap Around" is selected and the top and
bottom anchors stay in the middle; now, just add anchors that go back and
forth between the upper and lower anchors.
Image>Rotate Canvas>90 CW
Filter>Distort>Shear again. You can use the same points as before or create
new ones. Now, depending on how mixey you want it to look, you can keep
rotating the canvas at 90 CW and keep shearing it; I only did this once
more, and here's what the result was:
...And here's the original image:
However, I don't reccomend that you Rotate and Shear a bunch of times over,
because even at 3 times, the result is quite grainy (as seen in my example).
Enjoy!