There's a quick-and-dirty method I use for power weapons, that I've done before in some of the larger step-by-steps... but I thought it deserved its own post.
Step 1: Leadbelcher
|Coat the weapon involved|
Step 2: White Scar
|Paint lines like electricity flowing along the weapon. I usually cheat the lines a bit to follow edges|
Step 3: Glaze/Wash
Step 4: White Scar
|As the final step, go back in with the white and pick out some of the lines again. Not all of them, mind, just the areas that you want to emphasize|