Easy way to do it is to hollow out a depression using a pin drill (little hand held drill with miniscule drill bits) or by twisting an X-Acto knife blade to hollow out the hole. Paint the interior "cup" silver and fill the hole up with 5 minute epoxy (found in the hardware section of stores like Wal-Mart). This stuff dries clear and the silver inside gives the shine.
You can also try this method with Elmer's glue for shallower depressions. MV lenses are nice, but expensive.