its a tricky one isn't it.Perhaps what you could do is pin the pattern pieces on for the top and skirt and if there's enough for both, cut out the top, but put the rest of the fabric away with a note of which skirt pattern you planned to use. . . .. . . For those smaller pieces which are left I like to make garments which combine fabrics, for instance a jersey back and silk front tee, shirts with contrast collars and cuffs or sometimes use them for nice bags/zipper pouches etc.