I saw a very good tip a couple of months ago in a Threads magazine.  If your fabric is limited for a garment project, don't be afraid to piece some of the garment pieces!  For example, the sleeves in an aloha shirt are frequently wider than the folded fabric you want to cut them from.  You can piece a small section onto the wide part of the underarm (a hidden spot) to stretch your fabric and save up to 1/3 yard!  Be sure to finish those edges as you would the rest of the garment, or use a French seam to secure the raw edges.