Which method are you using to add your users?

So far, the most successful method I've found has been to have them log into
the gms.whatever.whatever and verify the time zone, then have them browse to
the gms.whatever.whatever/install to install the software.

Seems every time we've tried to install via sending an SMS with the link,
something goes wrong.

I was also hoping to be able to just add the users, without them having to
be a part of initial setup process, but that hasn't worked out.