Clear Wax goes hand in hand with Chalk Paint™ and should be used after every piece is painted and has been sanded. Basically waxing is the final step. Apply clear wax with a rag or one of Annie Sloan's beautiful brushes. Apply wax all over and remove any excess.
Some prefer to wax and then sand others like to sand and then wax. It's a personal preference but either way leaves your piece soft and silky. For extra smoothness use a fine grade sandpaper after waxing.