I am still trying to decide my three best choices. One problem is that my comfort sweet spot, appendix, is not very concealable, at least not with serious-sized firearms*, though I do have a Raven Concealment ACR en route, and will soon acquire a G26, to test the theory one more time. I am lean enough for appendix IWB to be comfortable, but anything carried there will print against the cover garment. Fortunately, enough folks carry electronic gadgets nowadays, so printing is not the liability it once was, at least not for square-cornered objects.
My reflexive (training-conditioned) sweet spot is 0300, because my duty pistol has ridden there since 1983, and rather than fight nature, I will normally carry in the same place during personal time. I am left-handed, but right-armed, and functionally amdidextrous with most handguns; drawing a heavy S&W L-frame from the then-issued low-ride swivel duty rig was very much a whole-arm gross motor skill, and the right arm has more elbow room inside most vehicles than the left arm, so carrying right-side seemed the wiser choice during my academy training, and I saw little reason to change when issued/mandated holsters became more sensible, and duty handguns became lighter and more compact.
When I retire from policing, which may be as soon as early next year, my "primary" carry placement may migrate toward appendix, if I can sort-out the concealment issue. One consideration may be dual appendix, which would balance/even-out the slight bulges. Another consideration would be to carry a serious blade at appendix, rather than handgun. This would be especially applicable at "left" appendix, while a handgun occupies the right-side appendix spot.
A major weakness of a clipped-in knife is the clip snagging on things, which can cause the knife to be pulled from the pocket by anything from vines, branches, straps, dog leashes, a seam at the hem of a cover garment, to, one time, the edge of a vehicle's wheel well, which destroyed a Mili's pocket clip. (The clip, itself, was merely bent, but one screw hole was stripped, making it pointless to try straightening the clip.) Inside the pocket, usually surrounded by some type of pouch or sheath, has become a favored means of carrying folders, though I continue to carry an Assist or Rescue clipped-in, balancing the need to quickly access an emergency tool, with the risk of loss.
Another carry method for blades, is a belt-mounted sheath/scabbard, for both fixed and folding blades. Depending upon belt width, I may use a kydex sheath made by either River City Sheaths (Mike Sastre) or Survival Sheath Systems (Robert Humelbaugh) to tote a Gunting, as the Gunting's ramp is ever-ready to partially open the knife unintentionally, so I prefer the security of a sheath to keep it closed, in addition to the extra security of a sheath over clipped-in pocket carry.
I have used pocket holster carry for handguns, up to the Ruger SP101 in size, usually in a Kramer pocket holster. The dynamics of a fight can make access to a pocket problematic, so I have not liked my only handgun to be inside a pocket. As age-related and over-use injuries have made recoil painful, I have drifted away from the small, relatively powerful handguns that I have carried in pockets.
I used ankle rigs in the past, finally settling upon the Alessi as the most comfortable. My lefty Alessi rig for the quite heavy SP101, however, finally failed the "stomp test," so I discontinued routine use of Alessi ankle carry. I can still run with an SP101 in that rig, as running causes less inertia stress than a downward kick or "stomp," but as a downward kick could occur during a defensive fight, loss of the weapon is a concern.
So, ankle carry is no longer a "sweet spot" for me, though I now have an Alessi rig for my Seecamp pistol, and for the G26 I plan to buy soon, so ankle carry for a secondary/tertiary weapon may well be in my future. While seated, such as when driving, the ankle is easily accessible, and there are other scenarios that might render an ankle easier to reach than one's other weapon.
Another idea is to sew, screw, or rivet a magazine pouch, and/or knife sheath, to the Alessi SP101 ankle rig that I no longer fully trust, to give a second life to the rig. I would not want my only spare mag, or only blade, to be at ankle level, but accessibilty options are a good things, especially as so many defensive scenarios could involve being on the ground, or croughing behind low cover.
Well, this post is starting to become a book, so I will close for now.
*"Serious-sized" firearms, to me, fire duty/service cartridges, and have gripping areas that allows a firm grasp and "normal" trigger reach. Thanks to my fingers being thin, especially my ring and pinkie fingers, a long grip is not necessary, but I like a substantial grip volume, and would rather not have to crook my trigger finger "just so," for a too-tiny weapon.