I do most of my leveling moving around on the parking site with a circular bubble level on the console. Next stage is pieces of 3/4 inch plywood for fine tuning on longer stays (street side needs to be 3/4 inch high on a level spot to compensate for weight of slideouts). I have two packages of Lynx levelers, rarely used.
I don't think a C needs leveling jacks, though many would not be without them on larger rigs. Very seldom have I been where I really needed to build up blocks or ramps to get level, and in most of those spaces, the range of travel of jacks would not have been sufficient without also putting blocks under the jacks.
I most often use my blocks to build a ramp to raise the front end so that I have more room to work when doing a chassis inspection or oil change in my driveway.