Quickshade is cool and they have some specific offerings however I used to dip models in Minwax polyshades Antique Walnut it costs about 1/3 the price. Just remember Antique Walnut I've tried others and they will not shade right.
The sergent in the picture was dipped in the Minwax, and then hit with matte varnish spray. I did a whole 2000pt army in a week with this technique.
My advice is to dip, flick off vigorously, wait 5 minutes, take a largish throw away brush, and use it to remove any pooling varnish. IE you get a big blob at the bottom of the legs or sitting on top of the models head. Just work it around. Or wipe it off with the brush.
I did 20
tac marines, 20 terminates, 3 dreadnaughts, and 2 predator tanks with this method in a week in my spare time. It actually gets a surprising number of compliments at the bunker.
For large vehicles the best method I've found is to get some largeish paint brushes like for house trim painting. Dip it in the minwax wipe off the excess, then use nice smooth strokes to apply it semi-thick to the vehicle. As it sets all the brush strokes will level out, and it will run into the crevaces. A smaller brush can be used to remove any pools on the tanks top surfaces.