What I've found is that the best way to build a
lightsabre prop that doesn't look like everyone else's is to go to your local
hardware store, and start looking at parts. Generally
plumbing parts make a good start- I recommend 3/4" or so diameter
piping, in two small sections. Find a nifty
doohickey to connect them together (there are many, many ways to do this). Find an interesting cap to cover up one end- unless you're building a
double lightsabre like
Darth Maul's. My brother-in-law used a button from an air horn. Gold washers make a good decoration, and they come in approximately the correct sizes. Handles can be made of almost anything- cloth, tape, etc.
Electrical tape is already black and shiny, and applies well, but slips a lot.
Duct tape is gray, and offers slightly better grip. Keep in mind that lightsabres are two-handed weapons usually! Then all you need is an interesting orifice. An adapter for going from 3/4" to 1" can work, any of several types of connectors, etc.
I highly recommend using one of the
Episode 1-style attachments, as the
original trilogy's will cause you to continually slap your leg while walking.
In short, go to your local hardware store, and
experiment. Plug things together. Ignore the
customer service people- they probably suspect you of making a
pipe-bomb or something. Don't tell them what you're doing, or you'll get some wierd looks.