the best, or what I imagine would work the best anyway, is a purchased base which has an inverted hook over the figure to rest an index finger. I can see this not only being comfortable, but as protection if, in the heat of rapid brushing, one were to rotate the figure and instead of whacking it off its feet, merely a finger was bruised.

I intend to mount my figures on a wire drilled & shoved up the leg, so I am mindful of this as I search along.