There are many positions you can wear a holster and all are up to personal preference. The positions of your pistol holster can depend upon your physical shape, your profession, experience and training! Your holster preference location will change throughout your firearm ownership that is for sure. Over the course of your firearm ownership you will also try different holster brands based on what you see online, see in person, or have suggested from a friend!
The IWB holsters are extremely popular for the concealed carry firearm user. They allow for an easier way to conceal your weapon by merely covering it with your shirt. With IWB holsters your shirt options do not need to be as lengthy or larger to cover the holster considering that most of the holster is inside your waist band and already out of view. However, one thing to keep in mind is that your pant size might need to go up a size or two depending on the not only the pistol you choose to conceal carry, but also the IWB holster itself. If you go too bulky on both choices you are going to want to increase your pant size. For those of us with a little more baggage around our waist line, IWB holsters can be a little difficult and uncomfortable to wear for long periods of time, or in a sitting position.
My personal preference has long been using an OWB holster on my waist. I have had a few different holsters over the year and there are certainly plenty of cons when it comes to the conceal carry aspect of the holster printing a little more on your waist band. However because of my ever changing waist line size, both up and down, I have found it is easier for me to reliably train and carry with an OWB holster. There is a certain OWB holster that I have been wearing for years now, and everytime I acquire a new pistol and choose that as my conceal carry weapon, I order a new version of this holster. Concealment Solutions has long been my holster brand of choice and their Cobra OWB holster is one of the more popular kydex holsters on the market.
No single person can tell you what is the guaranteed holster that you need to buy that will work for you. Ultimately talk to as many people as you can and read online as much as you can. Knowing that you might purchase a few different holsters as you find the one that works for you is perfectly normal and part of the holster process. Make sure you know what is most important for you and find a holster that matches your lifestyle. One other reason I prefer OWB and specifically the Cobra holster is because I spend lots of time camping, hunting, riding ATVs and dirt bikes, and the Cobra holster keeps my firearm tight on my belt that doesn't flop around, and it also keeps it a little higher than other OWB holsters that I have used before.
Training, training, and more training
More importantly than choosing the coolest looking holster and the best on the market is making sure you train regularly with the holster you conceal carry with. Muscle memory is key when ensuring you can properly respond to the situation set before you. Getting training for a reliable and quality firearms instructor is key to being prepared. Than practicing over and over again with the weapon at the range as you are once again, prepared to respond.
Ultimately, whether you choose IWB or OWB, the Magholder can be placed anywhere on your belt to compliment your holster and ensure your concealed carry setup is maximized and setup to protect you in every situation.