Don't bury it too deep!
When you first start carrying...the urge is to bury the gun deep, especially if you live or work in an social climate where firearms are unpopular. Holster manufacturers are quick to capitalize on this with things like J-clips, C-clips, and "tuckable" holsters.
The problem is...when you're being assaulted...you don't want to have the gun buried under too much clothing. And it's also less advantageous if you have to use a two-handed maneuver to access the firearm (ie untuck shirt, then grip).
For me personally - I like sport coats, oversize sweat shirts, sporting/photographer vests, and other sorts of garments that "swing away", and allow me a one-handed draw and reholstering from a strong-side OWB hip holster.