If you have a client using Godaddy, here's a quick tip for setting up a Godaddy domain for heroku.
heroku domains:add www.example.com
That's easy enough to go into Godaddy's DNS manager and add a cname for
www and link it to your heroku domain
But, heroku doesn't support naked domains (
Some providers like DNSimple provide
an alias for a naked domain. The next best thing is a forwarder. After
setting up your CNAME record, exit out and find the link to turn
forwarding on. Then, forward example.com to www.example.com (default is
301 permanent...you want that). Now you're good to go!