I take an old 5 cent coin from 1913-1928 Buffalo nickel and just start carving out the head or adjusting the nose or hair it?s like carving clay but with metal. I have hardened Cobalt engraving tips that have a bunch of different sizes or shapes for different cuts or smoothing out areas. Here is one of my web pages with before and after
http://www.healthfularts.com/hand%20engraving/Other%20Items.html
Hope that explains a little bit more for you.
Here is a link to a Step by step way of doing coins ( this is not me but some one else)
http://www.sga-sculpture-engraving.com/Pages/ella.html

There is nothing like being a Clown!