Something I have noticed online is that people talk about how they carry different firearms in different places on their bodies on different days. I think this is a mistake that could cost someone their life.
When I first started carrying about firearm for self-defense 4 years ago I debated carrying my Glock 19 semi-auto or my S&W Model 28 .357 revolver. They both are simple reliable draw, aim, and fire weapons with no external safeties to forget in a critical moment. The .357 is a proven man stopper, and the 9mm properly placed is no slouch either. I eventually chose the Glock because it was they only one I had a sturdy carry holster for.
I have carried my Glock as a concealed weapon in the same position on my body in first an OWB (outside waistband) and then an IWB (inside waistband) holster both at 3:30 (or just behind center on my right side). I carry 2 spare magazines at my 8:30 (or just behind center on my left side), a Surefire 6PLED at my 11:00 (or just to the left of my belt buckle), and a folding lock blade knife clipped to the inside of my right pocket.
When at home in the house, working the garden, or out in the woods around my home I open carry my pistol and also carry all but the spare magazines, and always in the same places on my body. The lack of spare magazines is less of a problem when I am at home and close to additional firearms. (I am not going to point out the benefits of always having a pistol, knife, and light in this post but I may in another post.)
If for some reason you absolutely have to carry different weapons consider ones that have a similar manual of arms (placement and use of controls) and function i.e. revolver or semi-auto. I usually carry a Glock 26 as a backup weapon and it is identical in every way to the 19 in every way except for being smaller and easier to conceal. I sometimes carry it in place of the 19 when I need an easier to conceal weapon due to having to wear business clothes.
Now I understand that environmental and fashion/dress code requirements can cause you to need to switch to a smaller weapon and/or move it on your body. My point is that you should pick a single handgun that you can carry in the same place in 95% of situations. Also carry your other gear in the same way every time. When you are at home empty your weapon (and double-check it) and practice drawing, aiming, and dry-firing your weapon. Use a snap cap or similar device to prevent damage from excessive dry-firing. Use your light and knife for household tasks and get used to reaching for them instinctively. You will build muscle memory so that in an emergency your hand can automatically find, grasp, and produce your firearm and/or light.