The fastest method is to rely on the plastic's color: paint only the parts which are different from the plastic color, then apply a dark wash. They turn out surprisingly well, and they're ridiculously inexpensive. The vehicles are the same: paint only that which is different from the plastic color (less paint to lose, overall…); apply a dark wash, followed by a matte, clear coat.
I use MinWax Polyshades (a.k.a., "The Dip", brushed on). The Polyshades keeps the paint on pretty well, though not perfectly. I just dump mine into a bin, when done with a game, and they've only shown a few paint chips, on the rifles, after several years of such treatment.
Some sort of base is really helpful in keeping the figures upright, as some are molded with a pronounced lean, which prevents them standing on their own. For uber-simple bases, try getting some peel-n-stick, vinyl floor tiles, in either a pattern you like, or black; cut into 2"-squares, and peel and stick, glue sides together; then use Hot Glue to attach the figures to the bases. It is not the best, visually, but it is quite simple, effective, and inexpensive (tiles are 12"-square, yielding 36 squares, or 18 finished bases, per tile, at a cost of around $0.70 USD per tile, or $0.04 USD/base). The black base can be explained to represent the area of control for each figure -- where they can reach out and touch someone. Depending upon rules used, base sizes may be larger, or smaller.
To dress up the vehicles a bit, and simplify tracking of ammunition, I applied peel-n-stick vinyl numbers to my tanks (black on tan, red on green -- easier to see than black), before applying the Polyshades. That way the Polyshades helps seal the numbers in place.
If you apply the Fusion for Plastic paints, or the other spray paints made for plastic, just use the uniform color, which will require painting only the non-"plastic" areas -- saves a lot of time, and effort. Cheers!
finds out what happens when Elves go bad...
