When I was eleven and started painting miniatures with enamel paint I would hold the miniature between my thumb and index finger and paint away, minis, fingers and all. Then I would finish off the top of the minis head last... My 6th grade teacher thought I was a smart kid, but it never occurred to me to mount the mini onto something while I painted it...I guess I proved him wrong.
What I do now, since as an adult it is not fashionable to have paint on my fingers all the time, I take a 1/4 piece of rod, dowel or tubing about 4-6 inches long and epoxy pennies to the top of the rod. Then I mount the miniature to the penny with some Removable Adhesive Putty available at any office supply store. Some miniature artists simply putty the miniature onto a 1 inch dowel, a small empty paint jar or something similiar, but I like the thin rod as it feels more comfortable and I can easily spin the mini around in my fingers.
I then have a block of wood with several holes drilled into it that the dowels slip into so that the minis are held safely. No chance of my knocking these minis over, even with my being as destructive as I am. 1 inch dowels, small jars, it is just a matter of time before I knock a mini over on one of those. When done painting, I cover the mini with a small plastic bag to prevent dust from landing on the miniature.