Tutorial: Generate a cool tech pattern
File / New: 500×300px. You can just work on the background layer. The color is irrelevant for this. Filter / Render / Coulds / Plasma. Choose any values.
Filter / Blur / Pixelize: X:10 | Y:10
Filter / Map / Bumpmap and enter the values of image below:
You should get something like this:
Next apply: Filter / Edge-Detect / Edges:
You can of course apply Colors / Brightness & Contrast to get some personal fine tuning. And also consider Filter / Enhance / Sharpen which looks cool too if you sharpen the image a bit.
Below you see 3 different versions of this and how it could look like!