Hi Kevin,
I use anything I can get my hands on. I have a large spares hoard from a misspent youth. So the usual historex, masterbox tamiya etc. I used to hate the scale and size discrepancies between the different makes but have learnt to embrace them for my dioramas. The pickelhaubes are from scalelink, most of the French Kepis and backpacks from masterbox and airfix, lots of airfix Ho/OO figs for the bkgd.
Rgds Victor