Me (raising hand). OK, so I had a little help with the sewing from my wife. It wasn't too hard.
Regarding material, the big question is, do they need to be waterproof? You didn't mention what they will be used for. If they don't, simple uncoated nylon or lycra should work fine. If they do, there are lots of W/B fabrics to choose from. Check OWF at the top of this page. They sponsor the site and they sell the hardware too.
I did (short gaiters, just above ankle). PU coated nylon, ordinary elastic band at the bottom, anti-slip elastic at the top, 2 grommets set into bottom elastic and hem on each side, piece of "stiff" braid cord ,one end with a stop knot, other end with a toggle (cordlock) Simple, not 100% waterproof, but OK in snow or mud, or bogs for a while.
Loc: On top of the North Downs, UK
When I made some a few years back for my husband, I used some light weight but tough PU coated nylon. Makes them wet proof as well as snow and leaf/twig proof. Socks don't get soggy or snargled up with sharp things when walking through wet bracken & heather (or rape seed stalks! Nasty, them things. Very sharp). Worn with trousers rather than breeches, they stop the bottoms getting clarted up too much on muddy tracks.
They do up at the sides with Velcro, have an elastic strap under the instep, a hook at the front to hook to his boot laces at the toe, and elastic round the ankle and the top. Dead simple, and made from a pattern scaled up from a diagram, as I recall.
I had great difficulty sewing them: turned out the sewing machine was dead. If sewing Velcro, use a Size 90 JEANS needle. For sewing elastic a STRETCH or SUPER STRETCH needle is best. A 3 step zigzag stitch is the best for sewing the elastic on.
Loc: Central Texas
What kind of gaiters are you talking about? A. Low-light-breathable to keep debris or snow out of shoes and socks without causing sweat? B. Low-waterproof for kicking through dew/rain wet grass? C. High, over the calf for deep snow? D. Knee-high cordura/balistic to protect from cactus, thorns, tough brush?
You can make any of these. Unless you are making C's for conditions where your life depends on your gear, a wide range of materials will work.
I make A's from bargain table scraps of spandex swimming suit fabric. This is surprisingly durable. I make them from a single piece, flared in front to reach down the shoe over the laces with a single seam up the front. They slip on like socks, then pull down over socks and shoes. A "coat hook" grabs the laces; a patch of Velcro keeps the heel down. They have no under-strap.
B's can be just about anything, depending on whether you want waterproof or not. Heavy pack fabric is not necessary. Again, I like to make them of one piece, flared at the bottom with a Velcro closure on the front and Velcro heel patch. Elastic goes in the top and bottom seams. Most manufacturers make these as simple cylinders - I like to flare the bottom.
C's are usually made with a breathable leg and a waterproof bottom. The waterproof bottom will sweat, but is useful in wet snow. Otherwise the gaiters will be pretty stiff in the morning. The bottoms need to be really tough - ballistic nylon or heavy cordura if you plan to use crampons. Some folks put a rubber or leather patch on the inside of the ankles to keep crampons from snagging. For heavy use in snow, you will need bottom straps and they need to be really tough.
I make D's from marine cotton duck or denim with velcro up the front and a flare on the bottom front. Marine duck is the better choice for tough conditions.
As posted by Frenchie some time ago, you might want to try:
On this site http://www.andersj.se/, click "gör det själv", then on the central part scroll down to "damask - hog modell n°1". If your swedish is crap, you have pictures, and PDF pattern at the bottom of text.
I made some technical fitted gaiters for ice climbing, I used material that was too thick and they were wicked hot and eventually the underfoot straps ripped. But they were pretty easy to make, I used that controlled exposure pattern. They probably wouldn't have ripped either had I used a lighter nylon
A few years ago, I made a pair of gaitors. The design was good but I found that the material I used was too flimsy (1.1 oz. ripstop nylon). I was trying to make them really light but that was a bad choice. I'm not a sewing expert, but I would recomment using stiffer fabric.
_________________________ Gear Talk There's no such thing as having too many sporks!
I made a pair without a pattern. I used early generation Gore Tex on the top with a cordura bottom. Today I would line them with lighter nylon, which I could coat for the ankle area and leave uncoated on the calf. I can use a sewing machine, but am no way close to really competent. They worked fine with a little tinkering, but the real issue was the zippers. I never could find decent zippers. The low grade zipper was the issue that eventually retired them.