For me, just about every question in life comes to :"What do you want, and what are you willing to pay (give up) to obtain it?" Same goes for concealed carry.
I most especially favor the Kel-Tec P11, second choice is a Charter Arms Undercover in 38SPL. in a non-descript IWB suede leather holster .
The law (about "printing"/concealment) was already discussed. Your personal dress style,, your own preferences in weight and caliber, your own body-style, the available arms and your preference/proficiency, weather. These considerations all may influence not only HOW you carry, but WHAT you carry as well.
I am over 55, with a bit of a paunch, so inside the belt, the Kel-Tec on the factory clip works just fine. Slightly behind right hip. It kind of squishes into my side, under the tail of a loose shirt if summer, or a sweater or jacket or parka as the weather goes cooler. Even when going in suit-and-tie, it hides quite well in that position (bigger guns do not huide so well for me in suit-n-tie). Spare mag in left pants pocket or holder inside belt on left side.
Experiments in alternative arms have been J-frame S&W .38SPL, S&W #39 9mm, Star Model BM in 9mm, a FEG copy of the Browning Hi=Power, or 1911; all in virtually the same way. All holsters used were IWB and provided about the same angle and position. The carry-mode and presentation and reloading did not vary that much..
There also was an experimente with the Bianchi "Federal Man" holster for the 1911, which held it outside the belt, high, with a forward cant, and thumb-break retention. It was useable for me ONLY if I were wearing a really voluminous parka or field-jacket. It gave a whole new definition to "PRINT". when I was younnger and thinner.
The comments about the fanny pack and the "persons" who carry them seem just about in the X-ring. I guess context meas something, however. If you are at the beach in nothing but your zorries and Speedo, a fany pack might be less obtrusive.
I have carried in my camera bag ( a good-sized shoulder-bag for a 35mm SLR with three or four lenses and a 2-1/2" S&W Mod 19 under the floor-boards) but I usually had the camera slung around my neck most of the time. I cannot say I was comfortable with the gun off my body, in a location and presentation that changed by the second. There are people who do carry in their day-planner or breif-case, but it is not for me, thank you. But if that is the only possible way,???
Practice, practice, practice. They say that when the chips are down, you will perform as you practice, and there are schools of thought on that, too. "Concentrate on one gun, and use that one all the time" vs. "Practice with and rotate your carry to include the three or four possible guns that you might happen to be carrying, so you have familiarity and habit for each one".
I just concentrate on the P-11 and the J-frame. They will likely be what I carry 99.9%.
Flash-in-the-pan