Here are a few photos showing up what drybrushing does. On that Pnather row from left to right seen from behind is a base paint only, a shaded model, and a shaded and then highlighted one. For the drybrush I used some base yellow paint with some added white and yellow, but I might have used some straight from the bottle Sand. For the Pz IVs I used Dark Flesh and it worked fine! Drybruhing should be done after you remove most of the paint from the brush and are left with a dry trace only (it's drybrushing, right?), and should be applied in vertical flicks. There's no secret at all about this, only that less is more and if you find you don't have enought contrast, don't add more paint, instead go over the drybrushing process again. Now that I've done the Panthers I'll concentrate on the other vehicles (FlaK, Recce, the one below, etc) before basing all at the same time for consistency.