In early days, you'd get a few in the middle of a goods train. Latterly, like all modern goods trains, all the same type of wagon, all the same traffic, no variety and no guard's van!
So, if modelled in original grey, you'd generally get a mixture 9though not always) and there would be a brake van. When orange livery came in, you would still get them in a mixed consist with fertiliser or Guinness, but increasingly rakes only - and fitted by now so no van. Latterly, in cream livery, they'd have been just in fitted rakes.
Incidentally, a bogie fert wagon would make a good kit or RTR project.