These were some practices where I lived, when cabooses were still in regular use:
Pacific Electric Railway, which, after the mid-1950's dieselized and was pretty much absorbed into Southern Pacific, used switch engines (mostly EMD NW2's and cabooses on its trains.
Union Pacific regularly sent the local freight out on the Anaheim branch with an NW2 and also a caboose.
Santa Fe used Alco-GE S2 and S4 switchers on "Road Switchers". A "Road Switcher" on Santa Fe went on duty at an outlying station such as Santa Ana or Fullerton, and had a road crew instead of a yard crew. Because they worked off of the road board instead of the yard board, road crew work rules applied, and that included having a caboose. They never got further than 25 miles from their on-duty point, and mainly switched industrial spurs and coupled cars into cuts to be picked up by road trains. On some northeastern railroads these jobs were called "drills". Except for the Los Angeles Division and the Valley Division (both in California), Road Switcher assignments usually were given a GP7 or comparable engine.
Yard engines which left the yard and went down the main line to switch industry tracks normally had a caboose with them.
