1. MAke a new sig wit watever u want ill use 400x150
2. chose the gradient tool and go crazy

3.then duplicate layer and filter>distort>wave and hit randomize a few times and change the blending options to lighten

you can do this as many times as u want but dont make it over rendered
4. now merge visible (shift+ctrl+e) and duplicate twice. The first layer: Filter>stylize>wind from the right then do it from the left on the other layer and lighten and merge visible

5.duplicate the layer Then do a motion blur (filter>blur>motion blur)

6. Finaly change blending options to watever you want but ill use lighten then u can fidle with the levels to change the brightness then colour it and your done

Happy sigging!