My approach, to make these figures have the appearance of Burgundian Ordonnance, revolves largely around adding cast metal plumes and some straightforward putty work (...as straightforward is the only putty work I can do!). Interestingly the image of mounted spear-armed troops by the Master WA, interpreted as a contemporary illustration of Burgundians, shows no plumes, only scarves and pennons attached to helms - but we'll conveniently disregard that image for the purposes of this post! [EDIT - see Jim Hale's comments below!]
So here's whats been done to these fellas, all of whom are Perry Miniatures Light Cavalry plastics. First figure on the left uses the brigandine and plackart body. As I'm getting lazy towards painting all those rivets, I removed them with a scalpel and smoothed with sanding stick. The right arm is one holding a sword with half-length coat sleeves over armour, which was drilled out to take a long metal spear (as a flagbearer). A coat was then built up with Green Stuff, instead of the brig. The contemporary reference for this is below; it's an usual combination of what appears to be coat over armour, with plackart over the coat. The image shows two small rondels on the chest, which could have secured the coat to the armour beneath? I've left these off my figure.
Next to him, an assembly using the arms with short brigandine sleeves. Again I smoothed off the rivets (more evidence of my lethargy!) and covered these with putty as coat sleeves. A hood, tied at the front, was added - inspired by the mounted figures in the Housebook Master engravings, which have long been one of my favourite images for reference material. I reckon I can pick out several items of dress and weapons which Michael Perry included in this box set from these images.
The other pair are just assemblies done with the aim of creating some combinations which I'd not done before. I have an eccentric aspiration to have every coustiller as a different looking figure, but not if I'll achieve this! Putty turned-down boots added to one figure. The flagbearer on the right is the brig and plackart body (again), this time with the chest cut-off at the waist and replaced with full breast & backplates from a figure in the Perry Foot Knights box. The right arm is a mailed sleeved longbow arm, cut away and drilled out.