At the time that I made this costume my wife and I already had a baby that was 6 months old. So for this costume we decided just to use the one we already had instead of making a new one. The next thing was to decide which Star Wars character to make the costume of. My two recommendations for babies are a Jawa and Yoda. Since our particular baby couldn't walk yet Yoda seemed like the better choice.
To start, I blew up a balloon about the size of our baby's head. I then covered the balloon in cloth (an old bed sheet) that was dipped in Elmers glue. Several layers were needed and it took about a week for it all to dry and become hard. This skull cap serves as a good base for Yoda's ears. To make the ears I cut some cardboard and folded and bent it into a nice ear shape. I taped the ears to the skull cap and used lots of tape to create a nice Yoda-head shape to the whole thing. To get everything nice and smooth I covered the entire head with shop towels and white glue. This creates a skin over the head. The shop towels have a texture to them so in order to smooth them out I painted on several coats of white glue, allowing each coat to dry in between. After lightly sanding I primed and painted the head green with a little air-brushing for detail.. I used some Halloween spider-web decoration stuff to create some tufts of white hair behind the ears.
Yoda needs a cane. So I made one out of newspaper and did the same shop towel/glue process on it that I did with the head and ear piece.
Next came Yoda's robe. I got some cheap fabric and traced our baby on it to create an outline of her body. I cut out two pieces of fabric and placed them together. I have no idea how to sew (I'd love to learn) so I had to use glue to attach the two pieces together. A quick slit up the middle of the robe's front finished it off. I used some old brown faux fur that I had to make a little belt.
The costume went together really quickly and looked pretty cute. The baby seemed to enjoy wearing it and thought the cane tasted good.
Most of the stuff that was used for this costume was junk I had lying around.
Instructables purists: This project was completed in 2009. I don't have full step-by-step photos. Please don't beat me up for using the Photo format.