We've all drawn our jack-o-lantern faces with sharpies, and then we've all struggled to carve perfectly along the lines. Using washable markers solves all of our problems -- missed a line? No big deal, wipe it off.
Have you ever seen clay loops outside of art class? These things work wonders on a pumpkin.
A tool you've probably never considered: Thai fruit carving knives. Those narrow and flexible blades are perfect for small details you never thought were possible.
Linoleum cutters aren't something we've ever considered for pumpkin carving, but they allow you to have much more control of your design. And who doesn't want that?