One long spiral cut makes a Bic Roundstick a much more comfortable pen. Real simple but make sure not to cut yourself.
Step 1: Find a simple Bic Roundstick pen.
Take out the ink and pen tip.
Step 2: Make the spiral cut
Make a 45deg cut near the base of the pen. Once it goes about half way through the pen rotate the pen around the blade. Spiral cut the pen barell all the way as far as you want to go.
Put the ink tube back in the barell.