Some cheese just isn't easy to handle with a knife — particularly if it's really soft or crumbly. Food weblog The Kitchn recommends a different tool for these cheeses: standard dental floss.
If you're spreading or mixing the cheese, this obviously isn't necessary, but if you need it cut into nice slices, dental floss is the way to go:
If the cheese is small, you can hold it in one hand while your other pulls the floss taught and does the cutting. For larger situations, place cheese on a surface, shimmy the floss beneath it, and simply slice up, holding both ends of the floss and crossing the two ends to complete the cut. Then repeat in equal intervals.
Just don't use the mint-flavored kind. Eww.
My Uncool Kitchen Tool: Dental Floss [The Kitchn]