This is a pretty simple project. The size of the box is really up to you. I made mine 1/2″ × 5.5″ × 8″ for the Storm Trooper and 8.75" for Darth Vader. The depth of the sides is entirely up to you. Mine are 4" and sandwiched between front and back. Glue and 23-gauge headless pins are used to assemble. I chose to paint mine black and white, keeping with the StarWars color scheme but I also considered staining the outside boxes orange in keeping with the Halloween season. If you use cedar, keep in mind it is a soft wood and carves easily but also breaks away so I used the tape and CA method to hold the blank to the spoil board.
A 1/16" DC bit works well and will cut all the fine detail. I have mine set for 90 IPM and a plunge of 30 IPM.
The body lifts off the base to place the tea lights. You could also make them without the base and just place them over the tea lights. If using outside, top coat with a waterproof clear finish like Spar Varnish.