First, go to your local fabric store and find the McCall's pattern shown here. Make sure to get the right size! Find some fabric that will work well for the top and the pants for Luke's costume. We used some upholstery fabric for the top and cotton for the bottoms. (Also find some black shiny flowing fabric for Vader's cape while you're there. A yard was PLENTY for me.) This was my first time to follow a pattern to make a costume, so for me, although this was an "easy" pattern (thank goodness!) it was still the most time-consuming portion of making both the Luke and Vader costumes. Follow the steps on the pattern to make the top and pants, omitting the karate belt.