One of the most important parts of our kit is our clothing. The most important considerations for long-term wilderness living are durability, movement and being repairable. Fine materials and weak stitching will end up being rags very quickly. Your typical backpacking and hiking clothes are entirely inadequate. Just like your tools, your clothing must be what you would wear while working construction. I know, I wear a kilt and we'll get to that.
We'll start from the ground up. First, and in my opinion most important, is footwear. I will always prefer boots of a moccasin type. Here in the U.S. most areas have snakes and it is very nice to have confidence that you are protected as high up as possible. My primary boots are custom made by Nathan deBridge from Soul Path Shoes.
They're from buffalo leather cut just below the knee and have a completely flat sole with a simple tread. I prefer this design as it keeps me protected from pit vipers, brier, nettles, sharp rocks and sticks and other potential lower leg hazards. The thin, flat sole conforms to whatever is beneath my feet and allows me to feel through the boot. This is especially beneficial when hunting on the ground so you can remain silent. Being so low to the ground makes for much better balance, which will keep you from injury.
My second pair is what I wear when the ground is wet and slippery and need greater traction. They are a vintage pair of custom W.C. Russell Moccasin Boots that I bought off some NYC hipster that didn't know what he had, 700 dollar boots for 40 bucks because they were too wide! They are very similar to their current Wyman model but made from heavy bull leather, mid-calf length to protect from snakes with an aggressive tread and heel. Search around for used items, you never know what you might find.
Be sure to never buy a boot with a too high of a heel such as loggers. Your balance becomes poor and being so high up, you become very susceptible to rolling your ankles. By always wearing heavy, stiff boots, you weaken your feet and ankles making you prone to injury.
Boots need to be protective yet supple, think ninja boots. Anything lower than 8 inches (20cm) will constantly fill with rocks, seeds, soil and all manner of debris. They will also offer little protection from lower leg hazards as mentioned above. Do not sacrifice safety for comfort, I've witnessed a hiker slip and impale their calf with a broken branch. Yes, your calves are going to get hot in the summer wearing high boots. So what, suck it up!
For socks I always wear wool, even in summer. A thin pair of wool socks are cooler and will keep your feet drier than cotton. I know there are some modern sports materials out there, and if that is you preference that's fine. I like to use traditional equipment as much as possible.
A variety of weights of wool socks will cover your needs. For winter you can layer them just like the rest of your clothes. A pair of wool felt insoles are great for winter too but nothing beats beaver pelt insoles for absolute warmth. The cold ground draws your body heat down and insulative insoles will do far more than the thickest socks for keeping your feet warm.
For my legs I prefer a filibeg (small) kilt for many reasons. You have absolute freedom of movement, no impedance whatsoever. In tick country, they are going to get on you no matter what. Instead of needing to drop your pants to check every time you feel a tickle, all you do is lift up your kilt. I wear my tools about my waist so this is a huge advantage. Which brings me to my next point; They are tactically sound.
In an area with dangerous game you are often wearing a pistol and when your handling "business", you are never caught with your pants down. All your tools remain about your waist at all times. You can even take care of your lady without ever shedding an article of clothing. Speaking of your lady, your bits don't get rank like they do in pants. Everything stays aired out and hygienic, no crotch rot.
In the winter they are very warm, A proper winter kilt is made from 9 yards of wool and with the pleats, there are at least 7 layers of very warm material at any one spot. When standing still, air is trapped and you stay warm but when moving, the kilt swings and vents keeping you from sweating excessively. Even in winter I prefer the small kilt due to balance.
A great kilt has almost all 9 yards of the top part of the plaid hanging off your backside when down and is very uncomfortable compared to the filibeg kilt, which has the same amount of material it's entire circumference when worn. Perhaps if I lived more northerly and would not wear the great kilt down and always had it up around my torso I would feel differently. For the summer I make my kilts from cotton plaid and reduce the material to 5-7 yards, still more cool than nylon pants in my opinion.
If your legs are skinny enough and your balls small enough for pants, stick with cotton or wool unless you are running around in buckskin. Nylon is VERY noisy and not suitable for life in the wilderness. Also, if an ember lands on your nylon it will melt right through burning you twice.
Cotton flannel and especially wool is silent and great for hunting and simply being able to enjoy the sounds of nature. Brushed twill works well too. Over high abrasion areas you can sew additional material, my favorite being supple leather. A gusseted crotch is great for mobility. Again, think work pants like such brands as Arbor Wear, Filson and Duluth Trading. I do not wear shorts in the wilderness.
If you wear pants, a good set of wool long-johns is a must. In a kilt your thighs share heat and stay very warm in cold weather but in pants they are separate and insulation is very important. Smartwool will work but Filson is a far more robust brand, their Alaskan-weight long-johns are very warm and tough. I don't wear panties, so you will have to figure that one out on your own.
For your upper body you need the greatest variety of layers. Layering makes for less to carry in the long run, offers a greater variety of options for different times of year and climates and is a lot easier to dry out if wet. A thick, heavy coat is hard to get clean, the insulation will retain odor and takes a very long time to fully dry.
My layers are as follows from warmest to coldest: cotton or linen short sleeve and long sleeve, wool base layer, flannel long sleeve, canvas jacket, light wool sweater, heavy (boiled) wool sweater, wool jacket and for wet weather a waxed canvas, oilcloth or oiled leather overcoat. A big fur is great but it just might get you shot during hunting season. If you wear a fur, keep the hide out, fur in so you do not get mistaken for a critter.
Waistcoats are nice too and great for mobility while keeping your torso warm. I really like a wool tweed, oilcloth or sheepskin waistcoat with plenty of pockets. A cloak or poncho is a favorite option too. While wearing it you can drape it over your pack and carry your rifle in hand and keep them completely out of the weather.
Hats vary greatly depending on environment. A wide brim is fantastic in sunny areas and in the rain but in the shaded woods they can block your vision and get you a stick in the eye, not to mention getting knocked off frequently. A short-brimmed hat looks sharp but dumps water down the inside of the back of your collar in the rain.
If it has a full brim, I like it wide. In the heat, straw and in the cold, felt. For a partial brimmed hat for the winter, I like a wool or mohair flat cap. It has just enough brim to keep the low winter sun out of your eyes but not too much so that it gets knocked off or hits branches when stalking through the woods.
Brimless headwear consists of bandannas in the heat and wool stocking caps or a Scots bonnet (Tam) in the cold. Loose knitted wool for autumn and boiled wool for winter. In the Far North, a fur cap that can cover your ears makes a great deal of sense.
For gloves, just a plain pair of leather ones that fit snug to the hand for when it is warm. In the cold, a slightly larger pair of leather gloves that can fit wool liners underneath. In the deep cold, a pair of fur-lined mittens so the fingers can share warmth and perhaps fit some wool liners depending on how cold it gets.
I have never had much use for finger-less gloves except for wool ones that have a flip-over mitten. Combine them with a leather chopper and this can be a good system for rifle hunting or setting traps where you need your dexterity but it is too cold to completely take off all gloves.
Scarves and neck cloths are essential pieces of kit. In the cold or in high winds, dust storms, pollen clouds or smoke you will be grateful to have something to cover your face. The material again depends on climate. In the heat linen is my favorite and in the cold, wool. For winter, a tube skinned coyote, lynx or wolf is awesome.
Lastly are belts and suspenders. I do not wear suspenders, but if you do, still wear a belt. Your readily used tools should be worn about the waist so a belt is imperative. Your belt should always be made from wide, heavy leather and solidly stitched or riveted at the buckle. A cloth belt cannot be used as a strop and does not work well for beating your children, woman or other members of your party. The buckle needs to be solid and not allowed to slip. The typical design is most effective.
That just about covers clothing. As you can tell, I prefer traditional, time tested materials and designs. Look to what people have traditionally used in your area or similar climates and regions, pick what you like from that and base your kit off of their wisdom. New man-made materials are generally noisy, flammable and difficult to clean and repair in the field. For long-term wilderness living, stick to the traditional and natural.