I use a di-Santis paddle often with a tee shirt over it. No one seems to ever notice.
When working in the yard I use a Blackhawk serpa ii paddle. Not the most concealable holster I own, but tuff, and comfortable. I can't count how many times I have needed something at the store and just covered it with a tee shirt for a run to lowes or Home Depot.
I rarely think about it unless going out to dinner or a movie.
Then I conceal with one of the IWBs.