Fancy knot tying is an art, but you don't need to be an expert to tie pretty knots. There are lots of step-by-step how-to videos you can follow to make knots that will impress your friends. With the right tools and a little practice you can tie everything from a long, four-bight turk's head to a gaucho knot, and more. The basic tool, and really the only thing you need to get started (besides string), is a knot needle (also called a perma-lok needle). This instructable shows how to make two different sizes of knot needles.
Step 1: Materials
I work in an office and there are always interesting things in the recycle bin. One of the things I keep coming across are screw-type paper fasteners. These fasteners are great for making para-cord knot needles. They're made of aluminum, and come in various lengths, with a screw-head on one end, and a threaded hole in other. Obviously, the long ones work best, but even a knot needle an inch long would work if you can't find a longer fastener.
I also found an aluminum rod at a yard sale, once, that started life as a gun-cleaning rod with threaded segments. This rod made a really nice long knot needle. You never know when you're going to stumble across just the thing you need for that future project.
For working the aluminum, you'll need a hack saw, a power drill, a file, sandpaper, and steel wool.
For the smaller knot needle, I use the plastic inner barrel that you find in some cheap mechanical pencils. In a pinch, you can make one out of a ballpoint pen barrel, but that's a messy proposition. It would help if the pen was mostly out of ink.
You'll also need a wood screw (just small enough to force inside the plastic inner barrel from the pencil), a sharp knife, and a lighter or candle flame.
Step 2: Making the Para-cord Knot Needle
First, cut the head off the aluminum paper fastener, being careful not to bend the aluminum. If it bends, you can pound on it gently to straighten it out, it's not a big deal if the knot needle isn't straight.
Mount the aluminum rod in the chuck of your power drill (protect the aluminum from the chuck-teeth with a wrap or two of paper before you clamp it in the chuck) and work the material down slowly by running it back and forth against the file. You'll develop a technique for moving the aluminum back and forth on the file, steadying it with a finger (don't be silly, wear gloves for this step).
In the second picture, I've made a rounded point. If you stop here and shine it up, it will make a really good tool for threading drawstrings through various garments (I am surprised at how often I find myself doing this). Keep working the aluminum against the file till you have a nice tapered point that will slide through a tight knot. Don't make the point sharp, though, or it will snag on the para-cord when you're tying knots. Once you get the point the way you want, smooth it up with the sand paper until there are no more file marks. To finish the project shine the knot needle with steel wool. If you want you can flip the knot needle around and chuck up the pointy end (protecting it with some paper) and shine the other end.
I have not specified any grades of grit for the sand paper, or the "0" size for the steel wool. It really doesn't matter, as long as you can get it smooth enough that the knot needle will slide easily through a knot.
Step 3: Knot Needle for 2-mm String
Take the pencil apart and cut the plastic pencil point off of the plastic tube. Work the wood screw into the plastic tube, trying to keep it as straight as possible. I use a lighter to heat up the screw a bit. Don't melt the plastic or burn your fingers. You only need to get the screw warm enough to make it easier to cut the threads. Keep at it until you get at least a quarter inch of the screw into the plastic. Remove the screw, and cut a sharp point on the other end of the plastic tube. You're done, now all you need is some string and a YouTube video.
I usually fold the cord in half and force it into the the threads while I'm twisting the knot needle to get a good tight fit. If you want to use smaller string, you can shove it into the threaded portion of the knot needle with a tooth pick and break of the excess toothpick.
I haven't included any pictures of knots, but I may add some later. This post is about knot needles, not knots... I'll see myself out.