Ready to learn how to design some cool looking magma from scratch, It's a really basic and simple tutorial yet effective and neat. I reccommend learning this cause it can be used to design various things. I used this tutorial not long ago and fixed it up to design fire for a client, it can be varied many ways and is very helpful.

Step 1 Begin with a size at least around 400 pixels, you can resize it later. Press the 'D' key then go to Filter-Render-Clouds.

Step 2 Ok now make a new layer, Layer-New Layer. Set the mode to color. And fill it in with blue. I partically used this color: #00478A Now merge the layers, press Shift+Ctrl+E. Now you should have something similar to the image on the left.

Step 3 Alright now duplicate the layer. Then add plastic wrap to the new layer. Use settings 15-9-7 in that exact order. Then select ok and go to both layers pressing Ctrl-I inverting them. Finally set the new layer with the plastic wrap mode to overlay. That concludes the Magma Tutorial.