Board Thread:Consensus Track/@comment-3076045-20131030000429/@comment-4787430-20131111192302

You make good points. Come to think of it, there is a banner atop a user's talk page when leaving a new message that tells you to sign using ( ~ ). Perhaps if that message was in it will grab the attention of the  user to sign their messages.

As for the talk page templates, (The auto-welcome message, I think you mean) the main welcome template can be updated to include a simple how-to of signing a message either using the four tildes or ~ button.