[header] How to make a pen [title] Shape a pen with polymer clay. [step] Take out a pen's ink cartridge and cut a bamboo skewer to the same length. Wipe the skewer with petroleum jelly and use it to pierce a small ball of polymer clay. 
Roll out the clay until it extends along the whole skewer, seal it over one end, and bake according to clay's label instructions. Let cool 5-10 minutes, remove the skewer, then glue in the ink cartridge once the clay has cooled completely.