Since I've started playing fantasy games more regularly now, I've been collecting figures. I started out with a box that I found when working as a grounds-keeper at an apartment complex (back in 1995). I was helping clean out an apartment after the tenants moved and was given the job of disposing of the remaining junk. A particular box caught my eye and upon inspection I found a bunch of old D&D miniatures, most of them made by Grenadier.
Years later I got some more miniatures at a yard sale. It was another collection of old fantasy figures from unknown origins. A number of them looked like they were intended for DBA (or something similar) and were painted like Vikings. There was also a group of goblin warg riders.
Recently I purchase another D&D miniature (a paladin archer), and grabbed a Mage Knight Rebellion booster box that was on sale for $3 at the local hobby shop. The MK box was a slight disappointment in that I didn't realize that the universe was Techno/Fantasy rather than High Fantasy like I was thinking. The figures are also a little oversized compared to what I've collected up to now. But there was one great find in that box: a figure called a "Spine Sucker" that really freaked out the players in one of the Dungeonation games played recently.
Given the success of that one figure, I kept an eye out on eBay for more cheap Mage Knight figures. This fall I found a group of 31 that was mostly suitable for fantasy, and at 33¢ each, was worth a shot. The quality is mixed, from Gnolls that are a perfect fit, to some excellent elemental monsters (where the scale doesn't matter), to a couple of oversized humans, and a skeleton that is way out of scale (I think this was one of a group of infamous early figures).
Since washers cost between 5 and 6 cents each, it is often cheaper and easier to base on US pennies (not sure about the legality though). I prefer to glue the miniature to the base (either with PVA or Superglue) and then cover it with white Spackle. When the Spackle is dry I then paint it in appropriate colors.
When I purchased a group of Mage Knight minis I did the same with them. It took me a little research and a couple attempts to figure out I could pry the figures off their click bases with a x-acto knife and a pair of needle nose pliers (to hold the base and keep my fingers away from the knife). For these I used Superglue to attach them to their new base.
A little putty (or spackle mixed with PVA glue) applied to the top of the base gives some texture and hides the penny face. I tend to use black or dark gray paint on these bases since they're used mostly in dungeon crawls.