Hi All

Sometimes more difficult to create good low-poly model that hi-poly and I'd like to recommend You really good and not expansive tool with help You to do this - Topogun

This small program allows You to "draw" low-poly topology on the surface of hi-poly model, Furthermore - all vertex of low-poly will be automatically "glued" to the target surface.
Program very easy to use and in addition has the features of creating normal bump, displacement and ambient occlusion maps.

Hope this information will be helpful

Vit