P.W.
you don't have to be crafty! Just tell kids to come as their favorite star wars character, buy star wars cake and prizes. Have star wars music going and make up a couple of Star Wars games.
put a black cape on a piñata (say it is Darth Vadar) and give the kids a light sword instead of a stick.
instead of pin the tail on the donkey. pin the ears on Yoda...... you can print off a photo of yoda from the internet.
If you decide to get sort of crafty...... go to Home Depot and collect all their big boxes. Tape them together to create a tunnel for the kids to crawl through. Name the tunnel some planet from the movie and let the kids go to town!