I received a very succinct and useful email about brush selection from Toko. Guessing that I'm not the only video-averse Ski Talker I'm posting the text here.
Steel Oval – this is an awesome brush but needs to be detuned before use. Rub it back and forth on concrete or asphalt for 30 seconds and you’re done. At this point, it can be used as a utility brush. If it is not detuned, it will remove a fine layer of base material. This can be useful for reconditioning bases, but this is a different purpose from regular brushing and is an advanced topic.
When I say utility brush, I mean it is your workhorse. It's the brush you use after you ski/ride before you wax. This cleans the base and opens it up such that it will accept more wax when you hot wax. Then it is the first brush you use after you scrape your hot wax.
Copper Oval – If you're not using the Steel Brush, this is your utility brush. Use the Copper after you ski/ride to clean and base and prep the base for hot waxing. Also this is the first brush you use after you scrape your hot wax regardless of what hardness of wax (yellow, red, or blue)
Horsehair Oval – The Horsehair brush has very fine short bristles. It is very aggressive in that it removes all wax from the surface of the ski and structure which is perfect for cold conditions. Use the Horsehair brush after the Copper or Steel when brushing out cold waxes such as Blue or XCold.
Nylon Oval – The Nylon brush has fat bristles which appear to be aggressive but actually are not at all. It leaves a light sheen of wax on the base which is not a bad thing when there is a bit more moisture in the snow. Use the Nylon brush after the Copper or Steel when brushing out Red or Yellow hot waxes.
Summary
After skiing and before waxing brush base out with Steel or Copper. Then hot wax, let cool, and scrape. Then brush with Steel or Oval as your first brush regardless of the hardness of the hot wax. Then if waxing with Blue (cold hard wax), brush out thoroughly with horsehair. If waxing with red or yellow (wax for around 20f or warmer) brush with the Oval Nylon.
Liquid Paraffin
If using liquid paraffin on top of hot wax, brush the liquid paraffin out with the
yellow liquid paraffin polishing brush. This brush should be reserved for just brushing out liquid paraffins. When a hand brush is used to brush out hot waxes the particles collect in the bristles. This would contaminate the liquid paraffin application. Liquid paraffin doesn't have such big particles and it's important that it goes on the ski on a very thin slippery laye