Personally I've found that nobody notices even if I swear someone does. They don't...So I tend not to worry too much. IWB w/t-shirt and shorts works fine.
The more you look like everyone else, the less people will look at you.
When you start wearing crazy stuff to "hide" your holster like oversized clothing and obvious types of attire people may assume you're hiding something or at the very least look at you more closely.
When I go out carrying, I look like I do on any other day and nobody says a word.