In this post, the miniatures I’m painting are four 15mm Minifigs riflemen. These are part of a pack of 24 that include 2 officers and 22 riflemen. The riflemen come in a single pose – running with their rifle. They rather remind me of this rifleman painted by Don Troiani.
The initial steps I follow will be familiar to other collectors. First any flash is trimmed or filed away, and then the miniatures are scrubbed with dish soap and an old toothbrush. Next the minis are mounted on popsicle sticks with white glue, and sprayed with primer. These minis were primed with gray (I’ve also used white, depending on availability at my local hobby shop).
Most of my riflemen have been painted wearing off-white hunting shirts, like the Troiani figure. I decided to paint this batch in brown, as this seems to have been a popular color among some riflemen living on the western frontier. Consider this description by Samuel Houston of Virginia's Rockbridge Rifles:
The men generally wore hunting shirts of heavy tow linen; died brown with bark; they were open in front and made to extend down near to the knee and belted around the waist with dressed skin or woven girths. The sleeves were large, with a wrist band round the wrist and fringed over the upper part of the hand as far as the knuckles. Under the hunting shirt was a jacket made of some finer materials, and breeches of dressed buck or deer skin to just below the knees, with long stockings and moccasins of deer leather... 
I won't be able to simulate this look exactly, as the Minifigs riflemen are wearing trousers, not breeches, and leather shoes, not moccasins.
The paints I use are Vallejo Game Colors. I start by mixing a modest amount of Cobra Leather with a larger quantity of Dead White and paint the trousers. Then I add a couple of drops of Beasty Brown to the painting tray. The brown is set down next to the leather/white mix, and by mixing them to different degrees in different spots, I create a range of browns. In one spot I also add a touch of Stonewall Grey to create a very pale brown. These colors are used to paint the hunting shirts. After that I add a single drop of black onto the mixed brown, stir it just slightly, and use this imperfectly-mixed brown/black color to paint the hats and feathers. Finally, I add a drop of Pale Flesh off to one side of the painting tray, get the brush good and wet, and paint the hands and faces of the figures.
I paint the rifles, canteens, and axe handles brown. I then add a bit of Dark Fleshtone to this color, and heavily dilute the paint with water to create a wash. Then I liberally apply this mix to the skin parts. I then add a small amount of black and some more water to the wash. I apply this to the hunting shirts, powder horns, bags, and rifles. I place a drop of black on one side of the tray, and paint the shoes and the metal parts of the rifles and axe blades. I then decide to make these riflemen sandy haired. I use Cobra Leather on two of the figures (this makes a surprisingly nice redhead at 15mm scale), then add a touch of black and use this on the other two. I like this mix and I apply it to one pair of shoes to give them a muddy appearance.
A mix Cobra Leather with Dead White 50:50 and use this mix to paint the straps and belts on the riflemen. I then add additional white to some of this mix and use this to repaint several pairs of trousers and a couple of powder horns. The rest of the mix is diluted with brown and I use this to highlight the axe handles and to paint several gun straps, and the backs of the powder horns. Finally, I use Silver and Brassy Brass on the metal parts and with black I do a little touch up here and there and paint the muzzle. By this time the brownish mix is drying out. Taking a ratty old brush I use this to drybrush a little onto the hat feathers. And with that, the figures are essentially complete.
1. Quote appears on p. 68 of L. E. Babits & J. B. Howard (2009). Long, obstinate, and bloody: The battle of Guilford Courthouse. UNC Press.