My thems big plumes ! OMG!
I just read a note; supposedly the much thinner French plumes on shakos assessed of
dh- on white- you have to build the colours.
First, I always undercoat in black matt anyway.
Second, a VERY light drybrush layer of a linen type shade (take your pick) up to a light tan wherever the white is to appear (and don't worry about overrun onto other details like belts!).
Apply several of these to build depth.
Thirdly, drybrush a light layer of white.
Drybrush means- not dripping with paint, no excess paint or visible 'shine' on the brush bristles. Only the merest tip is to be wetted and invariably I wipe it first on my palette, then on the figures.
Slow down the paint process to get slight, even coverage- leave under arms and in back joints etc. the darker linen shade to give shadow/ highlight contrast to the figures.
Above all paint a few and set them up as you will see them on the table, ie. mounted.
If you don't think it looks right, apply another shade of 'linen' undercoat over your whites and start again. Take your time and improve your technique- it will become easier, second-nature STS, and will save on paint in the long run.
Regards d