When you see blood.. [&:]
I use a 3 sided wet stone. I get it where I like and give the knife a few passes with a leather strap or belt. I can shave my arm hair, I have used it to cut 1/4" conveyor belt like butter where normally a utility knife is required. This all on my Kershaw Blackout pocket knife I carry and use everyday.
I have a Buck Zipper knife the wife gave me for Xmas one year while we were still dating as my field dress knife. Now that stays super razor sharp to split frog hair 3 ways.