Lately for metal figures I have been priming with thinned down Games Workshop Chaos Black (or whatever the new name) to bring out the detail in the figures. Although it takes longer to prime this way, instead of using a can of spray paint, it more than makes up for it with the detail easier to see.
My favorite figure of the bunch.
You probably guessed that this figure is from the Horse, charging, helmeted pack!
After viewing various sources on the web and in books, I decided I should do a test figure first. Even though I have painted many infantry figures, I wanted to experiment with different shades of brown to give variety to the figures as the "leather" would all be slightly different. The only exception I decided would be that the leather buff coats would be painted the same to give an appearance of uniformity to the unit. For the buff coats, I'm using a base of GW's Bestial Brown followed by two thinned down coats of Bubonic Brown (and I have officially stopped keeping track of the new names for the GW paints mainly because I can't remember what they are called and I don't feel like walking over to my painting table to check . . . okay, I got that off my chest).
I used a base of Bestial Brown for the horse followed by Snakebite Leather and a thin wash of Bestial Brown. For the blackened armor, I gradually built up the color with thinned down Chaos Black. Time consuming on the armor, but well worth it! The pictures do not really give the armor justice. The boots right now are just Bestial Brown but I will probably go over them with a dark brown wash and then give them some highlights with Snakebite Leather.
I don't remember where I read it first, but on another gaming blog it was suggested to keep a notebook journal on painting projects in order to "remember" how you painted a particular figure or how you did the basing.
Here is my painting and army organizing journal that I think cost around $5 US dollars at the local bookstore.
Just a few pages showing how I kept track when I was painting British WW II, Soviet Naval infantry and German Fallschirmjager (paratroopers) for Flames of War.
As you can see, I am keeping extensive notes for both the infantry and the cavalry. If you look closely enough, you can get a hint of the next infantry unit I will be doing!