there are several ways to make a provisional cast on
all of them exist to do the same thing--leave you with live stitches to pick up and knit with.
there is the EZ method, there are crocheted methods (several!) --you can just do a normal cast (a knitted one is best, long tail the worst!) with waste yarn, and then later undo the cast on.
Pick your posion! the end result is alwasy the same.. live stiches to pick up and work with-- (and live stitches are always 'stretchier' and cleaner than any normal cast on, and let a shawl (or what ever) fall and drape smoother.