Breaking-in and caring for your holster
Your holster will likely be tight when you get it. Some initial break-in work is performed before the holster ships, but additional work may be required. Here are some helpful pointers and safety tips for the break-in process. Please read them carefully!
When you first receive the holster, make sure your firearm is unloaded before checking the fit, or performing any break-in work.
When breaking in the holster, GO SLOWLY. Stretching the leather to loosen up the holster is fairly easy, but if you overdo it, there is usually no way to tighten it back up. Take your time, go slowly, and check the fit often, and you'll soon have a holster with retention that Goldilocks would deem "just right."
Before starting with the break-in, be aware that having the holster on your belt can affect the retention. You can certainly do most of the break-in work with the holster removed, but be sure to check the fit while the holster is being worn.
If your holster is too tight, wrap your unloaded pistol into a plastic bag, and then insert it into the holster. Remove the plastic-wrapped pistol about every minute to check the fit. (I recommend a plastic grocery bag because it is available to most people for free, and it is thinner plastic than many alternatives, which helps prevent unintentionally over-stretching.)
In extreme cases, when the holster is very tight, you may want to leave the plastic wrapped firearm in the holster for longer -- perhaps 5 minutes at a time. When doing this, I find it helpful to set a timer so that I don't forget. Set an egg timer, or if you have a smartphone, have Siri/Cortana/Google Now set a reminder.
If you're having trouble, or if you need any help, don't hesitate to let me know. I have quite a bit of experience with this, and I don't mind helping one bit!
It is always recommended to put on and remove IWB holsters by removing the belt. The snaps are like an ejection seat on an F16 -- you wouldn't use it every time you want to get out of the plane.
The belt loops on IWB holsters are intended to fit the belt snugly, so that the gun and holster won't wiggle and wobble on the belt. This aids stability, retention, and concealment. Because of this, the first few times you thread your belt through the loops may be difficult. Don't worry, they'll loosen up a bit over time.
The belt loops do have snaps, which are there to provide a way to quickly remove the holster when necessary (to disarm before going into the post office, etc.). However, due to the snug nature of the belt loops, putting the holster back on will usually require unbuckling your belt, and threading the belt through the belt loops, just like putting on an OWB holster.
The belt loops were not designed to allow the holster to be put on without removing the belt. Although this is sometimes possible after the belt loops have broken in (depending on your belt), it was not the intention, and tends to be hard on the belt loops.
The snaps I use are Pull-The-Dot one-way snaps, which only unsnap in one direction. This prevents the belt loops from accidentally coming undone. However, that does mean that they need to be snapped in the proper order. First, the bottom of the snap socket needs to engage the stud.
Then the rest of the snap can be closed.
The snaps can be a bit tight when new, but will become easier to use with a little bit of time.
Caring for your holster
DO NOT oil your holster. The leather is supposed to be stiff to maintain long-term retention. Using substances like Neatsfoot oil, Mink oil, or Olive oil will make the leather soft and floppy.
If your holster gets wet for any reason, it's VERY important to let it dry out. Take off the holster and remove the firearm (being careful to maintain the proper shape of the holster) and set it someplace where it can dry. If possible, set it in front of a fan. Let it dry completely before using it again. If you sweat a lot, or live someplace with high humidity, I advise rotating holsters every day, which allows each holster adequate time to fully dry. This will greatly extend the life of your holsters.
If you have to remove your firearm from the holster for an extended period of time, it's a good idea to take off the holster. Avoid sitting or laying on an empty holster. The three-dimensional shape of your holster is beneficial to proper retention, and also to safe one-handed reholstering.
When you aren't carrying, don't store the gun in the holster. This allows the holster to breathe and for any perspiration to evaporate, and also helps prevent any of that moisture from attacking your firearm (which can result in finish damage and rust).
If you holster gets scuffed, or just starts looking rough and old, I recommend applying a thin layer of Kiwi neutral shoe polish, or Renaissance wax polish. Let it dry to a haze, and then buff it off with a clean cloth. (Note: I recommend against using colored shoe polish. If you do, the color has a tendency to rub off onto your clothing.)
Avoid bending your belt at sharp angles. Doing so breaks down the fibers, and reduces the belt's rigidity.
When not in use, don't coil your belt up any tighter than it was in the shipping box. The ideal way to store your belt is to fasten the buckle in the notch that you use most frequently (which will retain the curved shape of the belt).