I ripped the paper towels into strips. Working quickly I dipped the strips in carpet adhesive and smeared them on the skeleton. I did several layers, including some strips that I braided or used to create "lumps" on the skulls. You should work quickly because the adhesive becomes tacky very quickly. Make sure to pose the skeletons in the positions you want them to remain in as this will make them harden much like paper mache.
After allowing them to dry for one to two full days, use a to gently rub stain all over the skeletons for a more gory look. Now you've taken those inexpensive non-scary skeletons and turned them into a showpiece decoration!