This might seem kind of silly, but I have separate V-Folders for each county I'm interested in, as well as separate V-Folders for aircraft, railroad, gas and electric utilities and local ham radio repeaters.
It's an organizational thing. At first I found having 20 scan lists to be very liberating (especially after suffering with my Pro-96 for so long), but I now find it restrictive and this was my way to deal with it. After a while I got used to pressing FUNC-PGM and loading different V-Folders as I travel across the metro area.
This is a rather extreme example from my V-Folder list, Hennepin County: Scan lists 1-10 are individual cities I find myself travelling in (I usually group PD and FD together for the same city, like Minnetonka or Hopkins, but Minneapolis has so much activity that I spread PD and FD out over scan list 9 and 10.) Scan list 11 is Hennepin County sheriff, 12 is all other Hennepin county police and 13 is all other Hennepin fire. 15 is University of MN police, 16 is MN State Patrol, 17 is for mutual aid TGs and simplex freqs, 18 is general use frequencies (GMRS/FRS/Dot/Star/etc...), 19 is Metro EMS and MED freqs, and 20 is Xcel Energy TGs for the west metro. I also have relevant amateur radio repeaters assigned to skywarn.
Others are far simpler. It's easy to fit scan lists for each individual city into most of the other V-Folders setups I have. Others, like aircraft, I have one scan list for general aviation frequencies and others for individual local airports. For amateur radio I have scan lists organized by band (6m, 2m, 70cm, etc...)
I kinda wish I could have multiple scan lists that I could pick from a menu with the arrow keys, and bind the number keys as 'hot keys' to my favorite scan lists. Needless to say, I am also very interested to read how other people have organized their scanners.