Not just another carry question (at least I don't think it is)

So my question (the question of a major newbie, so I apologize in advance) - what do you feel are the most important aspects of what you've decided to carry? Is it width, length, height, weight, capacity, caliber, style, manufacturer, or do you just find something you shoot well and figure out how to carry it later?

When I first got my LTC - almost 20 years ago - I based my carry decision on what I was most capable with. Having tried several of my handguns on the range prior to the qualification process I stuck with the one that I scored best with, which was my Sig P220. I had several other options, sizes, calibers, etc, but why carry any of them if the Sig was the best performer in my hands? It was many years before I opted to carry something different. And once you commit to a particular pistol you'll figure out how to CC it well. I've never had any issues or challenges with the P220 and never have had a "blown cover" event. And I've never thought twice about the capacity of the P220 with a couple of spare mags.

Now, with that history of CC, I've recently switched to an M&P Shield 9. And this choice was made in consideration of weight and size. Sub C's weren't always available during the course of my CC and I hadn't taken the time to look at new products in the gun world in many years. But once I did it seemed like a logical option to downsize the physicality of my carry while maintaining decent firepower. I keep the 8 rnd mag in mine with 2x 8 rnd spares and put the finger rest/base plate on all 3 mags.
24 rnds of 9mm critical defense will do just fine and I can carry the Shield anywhere from AIWB to 5 o'clock comfortably in any attire the season calls for.

I live in a state where I can't have more than 4 carry guns on my license. So that is one limiting factor, the other is I have arthritis in my hands and can't shoot the smallest guns well any more. When I had to list the 4 I would carry I had to put some thought into it.
The smallest gun I can shoot well is a Walther PP [ just a little larger than a PPK] And what I decided I needed was a small gun I could pocket carry. That is what fits my lifestyle best. I also wanted a medium size gun that I could shoot better but only carry when I was wearing cloths that would cover it. and a Large gun with better sights for those times when I felt I needed more. The fourth spot I added a J frame revolver.

With all that said I almost always carry a 9+1 32 auto that fits well in my pocket, I can shoot it well out to 30 yards, and it has enough grip to get all three gripping fingers on it. It also is easy to get off the second and third well aimed shots from. Its just a little smaller than a S&W Shield. Once I leave CA I think Ill be adding a Shield . I have been shooting my sons while he is deployed and I will not be happy to send it home with him when he returns. It's about the biggest gun I can pocket carry easily.

I have not cc'd the large or medium guns in over a year. Pocket carry just fits my lifestyle and needs.

When you boil down your needs and wants to what really matters it will help you decide what to carry. DR

I'm gonna break the chain a little. I'm not going to suggest a firearm. A good gun belt really is a necessity. And find a firearm that fits YOU. Try to find as many as you can to try out the grip. If it feels like it fits your hand, you're halfway there.
Now for breaking the chain... Study the laws in your state. Find out what ramifications you will encounter if you're involved in a self defense shooting.
Get some good insurance. If there's any kind of cloudiness in an investigation, you'll probably need bail money..
That said, you are using a firearm to STOP a threat. Not to wound a bad guy. You shoot until they stop. Prepare yourself for that reality.
It is a very huge responsibility to carry and you represent a large community. Conduct your lifestyle as that representative.
And lastly... Study..Know the law... And practice, practice, practice
Stay safe and welcome

As others have said, it is a combination of a variety of factors, INCLUDING your body shape and size and the resulting ability to conceal a particular firearm. You might also consider the clothing you do wear or must wear (as in a work uniform). Can it conceal something larger? For example, I can't carry my G19 or G30 very well unless I'm carrying IWB and wearing a shirt with a few wrinkles and some kind of print pattern. With the 19 I can get away with OWB in a Bianchi 82, but only if I'm wearing a darker, well patterned Hawaiian shirt. If your physiology is similar, can you wear a Hawaiian shirt every day? If I'm carrying my XDs, the foregoing requirements will depend on whether or not I am using the standard mag or the extended mag - and I'm not extremely comfortable with the standard mag because I can only get two grip fingers on it and the pinky slips underneath...so if I'm carrying the XDs it is almost always with the extended mag. With the p938 or p238, I can carry IWB VERY comfortably in a Black Arch or even a simple IWB like an Uncle Mike's. These give me 7 rounds with the pinky extension mag, and I do carry them from time to time, but mostly I will be carrying the p238 in a belly band on trail runs, and even in skimpy running shorts and a very thin dri-fit shirt, an uniformed passerby would never even suspect I was carrying. That said, I prefer a higher round count than the 938 or XDs can afford me, so I carry the g19 as often as I can get away with wearing a Hawaiian shirt. Finally, depending on the politiks of your state, you may have to list the weapons you certified with, as @dangerranger said. Looks like he's not far from me (Central Kalifornia -the People's Republik) and states he could list up to 4. State law allows 3 spaces for listing certified weapons on the CCW license, as I understand it, but some county sheriffs allow others/more to be listed. No so in my county...3 only. Here, you are stuck with those for 2years, until you re-up your license, when you can add/change listed weapons. If you have this restriction, consider it carefully. As my Utah CCW instructor advised us, don't be surprised if you end up with a big box full of holsters and maybe a couple of guns that didn't quite work. Spend time with the weapon(s) and holsters at home. Get to know what is comfortable and what is not. If you have an SO, have her look you up and down to see if you are printing while you are at home practicing. If there is no SO in the picture, make sure you have a long mirror to inspect your profile. Don't worry so much about a little bump, but do worry if it looks like a pistol grip...there are lots of folks out there who wear insulin pumps, holter monitors, and chemotherapy delivery systems, so a little bump doesn't matter. If anyone ever does ask, just tell them that's where you keep your "shots".

Finally, if you can find a good LGS that has a good selection of guns as well as holsters, some will let you try various combinations if it looks like you will buy one of each that works best for you. Good luck.

Weight was my first consideration and I chose the .380 over the .32 because there was not that much difference in the weight but the .380 performs so much better in defensive situations. I have heavier calibers but I don't carry them on me. The LCP is a lot cheaper than it was when I bought mine and then I customized it myself until it is about like the LCP custom that you can buy today. I went with the stainless return rod but after trying the heavier return spring I think that it was causing FTE so I went back to the original return spring. I carry in the reactive pocket Holster that came with the Viridian green laser that I installed on the LCP. I carry one in the chamber and seven in the magazine or if I sense that I might need more I go to the ten round magazine or the fifteen rounder. I carry 2-15s , 2-10s and the 8 in my car now due to the lawlessness that seems to be tolerated around the country right now. I normally carry a ten and the eight at home but then I have other guns to chose from at home.

My carry has evolved over 20+ years.
Started with 5 shot snub or Mustang Pocketlite 380 (choice based on easy to hide)
Moved up to Glock 26/27 when they became available, incorrectly thought this was as big as I could conceal effectively (appendix IWB) for years.
Eventually (few years ago) discovered that I could conceal a 19/23/32 just as well, so moved up to that and never went back down in size.
Hasn't always been just Glock I experimented with other pistols, gave 1911's and XD's a shot too.
I dislike having to disengage a manual thumb safety (1911) and the XD's did not do as well as Glock in 2nd shot average (higher bore axis).
Started doing "tests" to determine which I shoot best quickly with an accuracy requirement (double taps on 6'' circle placed at about 6 yards)
My 2nd shot average time difference in calibers is minimal given same size pistol (19/23/32) about four or five hundredths of a second.
About a year ago, I got a Glock 21 and once again discovered that I could conceal a bigger pistol than I thought, 21 gets carried a lot.
A Glock 43 or Kahr PM9 in pocket is what I carry when I can do no better (after work, dress clothes) otherwise it is a option carried with a bigger pistol.