I carry in what I wore for undercover work- a Blackhawk SERPA n my right side with the belt loop attachment and a matching Blackhawk double stack double mag pouch on the other hip- I wear a tank top or T-shirt under a Polo or button-down collared short-sleeve shirt- or even a Tshirt over a tank top- the ride height is high enough that my G20 does not tick out the bottom, and it's comfortable for all-day. The finger safety on the SERPA is very instinctual to release your weapon.
Your body type can be a factor in holsters- I'm 6'1"/190#, so my shirts drape well for belt slide carry, and my waist is trim enough that most IWB's irritate my waist. Sometimes if I',m being lazy I'll drop my S&W Scantium/Titanium .357 in my back pocket and it orients itself the same way each time, and being hammerless with a really heavy trigger, I don't worry about ND's having it loose in my back pocket- but I'd never carry my Glocks that way.