First go
Had my first go at drybrushing tonight. Went well, actually. I was quite pleased with myself!

I did 4 wagons, and also loaded them up with coal. No piccies yet, but I will put some up when I can.
Here is what I did:
Try to open bottle of Floquil Grimy Black.

20 mins. Pliers, wrench, door jamb, hammer, vice..... nup...... stuck fast that lid was. An easy way of opening stuck Floquil bottle lids would be FAB!
Got the smallest brush I could find. 2mm (1/16 "), dipped in the paint (Grimy Black), then squeezed/press between absorbent paper. Did a test squiggle on a separate sheet each brush refill, to make sure there was minimal paint.
Then brushed lightly along the joins/rivets etc. Also pressed quite hard to spread the brush bristles right out as well.
Should I use a bigger brush, or is the brush size dependant on the detail/spread of the weathering you want? Should I only use light strokes, or is pressing the brush quite hard to spread the bristles OK?
Rivets and rasied textures on the cars where OK, but the crevices proved a problem, getting the weathering down them.
What can I do about crevices?
Anyway, I was quite proud of myself!!! I was sure I was gunna wreck the paint job on the trucks, and have to repaint the whole thing, after I'd spent hours putting the decals on!