Binding One Mesh to Another I have 3 meshes: female feet, male feet (a shape key to female) and shoes.
When I morph the first mesh into the second, I need the third to follow. Binding shoes to female feet with Mesh deform is not an option since  the former are bigger than the later and are not being fully affected.
Is there a way of achieving it without scaling the shoes or feet?
Perhaps a shrinkwrap modifier on the shoe? But to be honest this might be a slightly more complex setup.

Some others ideas:
Use a driver linking shapekey influence to a shapekey on the shoe.
Use shrinkwrap but with a simpler mesh, that in return influence the high res shoe through a mesh deform. 

Got to see your file for more help.