This tutorial is for Paint Shop Pro 7, but I don't see how it couldn't be adapted for later versions or to Photoshop.

First things first, we need a pick to add the lightsaber to.
So here's one I made earlier.


To start off create a new raster layer.

Select the line tool with anti alias checked, the colour should be white and the width should be a little thiner then the image's lightsaber hilt. Also select the rounded cap end in the customise options.



Draw the line, starting from the hilt up to the tip of the blade.

Rename this layer to "Blade"



Using the wand, select the blade to highlight it, then create a new layer.

fill the selected area with the colour of the lightsaber you want, usually green, red or blue.
Once you have the selected area filled, deselect it. don't worry if it's jagged.
Rename this layer "Glow" then duplicate it twice.



With the the first glow layer selected, go to effects-> blur-> Gaussian blur.
Set the blur to 10 and apply.
Repeat with the other two glow layers, using 20 and 30 respectively.

Go back to the "Blade" layer and select Gaussian blur again, only this time select 2 and apply.



Finally, set all layer blending properties to screen.

And we're done.

This is just a rough guide and can easily be adapted and adjusted to preference. Use any glow colour you like, just so long as the blade is white.

Happy Editing and May The Force Be With You.

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