I use a sheet of glass as a cutting surface when I'm covering, which gives me very clean, sharp edges but eats up blades in a hurry. I keep a sharpener on the bench, and make a couple of passes over it whenever the blade starts to pull slightly on the covering. The sharpener I use is no longer available, but works like this one:
https://www.sharpeningsupplies.com/W...-P1820C18.aspx
I can tune up a dulled blade faster than I can change it.