Whether you're shopping for your first carry system (a carry system is defined as a gun plus holster), or are looking for something newer, easier, or just different than what you have been wearing, price, quality, and carry style are a few factors to consider. But Accessibility, Concealment, and Comfort are probably the three biggest factors to weigh when considering the holster part of your carry system.
ACCESSIBILITY — how quickly you can get to your gun — is a far more important than the type of gun you carry. Provided you keep control of your firearm, you can’t get to your gun too quickly. When shopping for a carry system, look for a combination that gives you rapid, efficient, controlled and instinctive presentation. That could be an inside-the-waistband (IWB) or outside-the-waistband (OWB) holster positioned on your hip, your center line (a.k.a., “appendix carry”) or your ankle. It might also be a pocket carry holster. Or a holster inside a specially-made garment. There are also options for off-body carry (e.g., in a purse or briefcase), but quick accessibility might be compromised if your firearm is not directly on your body. Of course, not every carry system is suitable for every person, given body shape, dress, skills, etc. The only way you’re going to know what works for you is to try it. Wearing the clothes you are likely to wear when you’re carrying, try as many different types of holsters as you can with your safety-checked firearm.
CONCEALMENT. Plenty of gun people say “concealed means concealed" and in no want do they want anyone to know they’re carrying a gun. If that’s you, choose a carry system that hides your gun without “printing” (revealing itself by making an impression on the cover garment). Again, it’s a process of trial and error, using various carry system with your normal clothes. All your clothes. You may have different clothing for different occasions that require different carry systems. A scrub-wearing medical professional with an ankle holster may switch to an IWB holster when wearing casual clothes. Women wear dresses, skirts, shorts and pants; all of which may require a different carry system.
COMFORT. Do you believe that conceal carrying a gun should be comforting but won't be comfortable? You want BOTH. If your carry system isn’t comfy to wear, there’s less of a chance you’ll wear it consistently. The only way to know if a carry system truly will be comfortable all day, through a range of activities (driving, walking the dog, shopping, sitting at a desk, working in the yard, carrying a kid, etc.) is to try it. And try it again. And again. It may take lots of experiementation before you'll be able to wear any outfit while concealing effectively and comfortably, but it’s worth the trial and error to figure it out.