funky colors
This will teach you how to create these funky shaped colors i used in some of my former work. Take a dark color as background if you want it to glow at the end. Now select the Lasso Tool by pressing L once and select a nice round selection close to mine on the left. Try other types of Selection-Tools to get another result at the end.
Now you want to hit Ctrl+Shift+N or just click the "New Layer"-Button to create a new layer. Choose a nice saturated but not too strong color now and go to Edit -> Stroke. Insert Width: 1px, Location: Center and lower the Opacity to about 30%. After clicking OK you'll see a very thin line in the color of your choice on the new layer. Since not very impressive, yet, we'll just proceed with the next step.
Now for the tricky part of it: drag your new layer on the New Layer-Button to clone it and press Ctrl+Down to move it down a pixel. Repeat this step with the new layer several times and you'll see what this is leading to. Remember it's a lot easier if you just merge down (Ctrl+E on the upper layer) every now and then. See how the whole thing is becoming nice when the shape overlaps itself?
After repeating the last step to your satisfaction, merge down all your color-layers and double it a last time. This time dont move it, but set it's blendmode to Overlay to enhance coloreffects.
Try this tutorial with different types of selection or move the copied layers into different directions to change the result. Also make sure to add some nifty 2D-Stuff or something.
done.