Sam I use a roller cutter for cutting patches. I have a pattern for every bullet I use and when I need patches I scan the pattern sheet and staple it 12 to 16 blank sheets putting a staple on every strip this keeps them straight and they are all the same when I cut them. I can cut around 360 patches in less then a hour with very little waste.
Rowdy Rick made me a patch board for cutting single sheets like Frank posted here once and it works great if I just want a few test patches cut. You can set the angle and with and length of the patch easy.
IMG_0538 by
Kurt, on Flickr