Mount dull broadheads on shortened arrow shafts for sharpening. I find that these lengths are easier for me to handle while sharpening than full length arrows. This is also a great way to use broken or crooked shafts. Cut the shaft six to eight inches long and taper the end, if necessary. Secure the broadhead with a heat-based glue, such as Ferr-L-Tite, and sharpen away. Then I simply mount the sharp broadheads on my hunting shafts.
I use an inexpensive pistol case to carry them to work so I can sharpen broadheads on my break. (Be sure to check with your employer before taking broadheads to work.) The black tool in the photo is an Arrow Grabber. This tool was covered in a previous tip.