Faux Render

Step 1.

Start a new document of any size, I'm using 800x600 here, and fill the background with black (#000000).

Step 2.

Press 'D' on your keyboard to reset your colors to black (#000000), and white (#FFFFFF)

Create a new layer, and make a square selection similar to this one, using the rectangular marquee tool:

Step 3.

Get out the gradient fill tool and set it up like so:

Mode set to Difference

Also try adding in a few gradients with the Linear Gradient tool as well with these settings:

Mode set to Difference

Now begin to fill the selection with a few gradients, clicking and dragging in different areas of the selection until you have an interesting look:

Step 4.

Press CTRL + D on your keyboard to deselect the area.

Now go to Filter->Distort->Wave and apply these settings:

You may need to press "randomize" a few times until you get again, and interesting look.

Result:

Step 5.

Now create a new layer, again with the rectangular marquee tool make a selection similar to this:

Get out the gradient tool again, and make sure the settings are still the same:

Mode set to Difference

Also try adding in a few gradients with the Linear Gradient tool as well with these settings:

Mode set to Difference

Now begin to fill the selection with a few gradients, clicking and dragging in different areas of the selection until you have an interesting look just like we did before:

Step 6.

Press CTRL + D on your keyboard to deselect the area, go to Filter->Distort->Wave and apply these settings:

Change the blending mode of this layer to "Screen" and drop the opacity down to around 83 percent:

Result:

Step 7.

Create another layer, and make a selection similar to this one using the rectangular marquee tool:

Get out the gradient tool again, and make sure the settings are still the same:

Mode set to Difference

Also try adding in a few gradients with the Linear Gradient tool as well with these settings:

Mode set to Difference

Result:

Step 8.

Press CTRL + D on your keyboard to deselect the area, go to Filter->Distort->Wave and apply these settings:

Drop the opacity of this layer down to around 85 percent:

Result:

Step 9.

Now you can continue to add a few more of these "blotches" if you want, but to keep this tutorial readable I;m going on to the next part of the faux render process...

Merge each of your layers together (except that background layer) by pressing CTRL + E on the keyboard.

Step 10.

To add color to the faux render, press CTRL + U on the keyboard and apply the following HUE/SATURATION settings (or choose your own color(s)):

Step 11.

Press CTRL + J on your keyboard to duplicate this layer, and change the blending mode of the duplicate layer to "overlay" and drop the opacity of this layer down to 70 percent:

Result:

Here's what I came up with after adding a background and a few little tech brushes.

Just have fun and explore different settings and blending options.