This is how I make strings. Wrong or right, it's how I do it.
First I lay out a couple kitchen chairs and weight them down with something so they don't tip when I got the threads tied on and am twisting them. I make 2 ply strings, twisted up by slightly reverse wrapping em. If slighty reverse wrapping scares you too much you don't have to do that, but I just prefer it either way compared to the loose twist of a typical flemish twist. Works for me. I lay the chairs out about a foot and a half to 2 feet longer than the bow I am making, gives me a good amount of leeway. Here I am using 20 strands of good quality linen thread. This string is actually for a warbow. After tieing 20 strands out between the chairs, I wax each one up and down with beeswax.
I separate the strings into two separate bundles of 10 each. Then twist each bundle up a bit, both bundles are twisted in the same direction, I loop the first around the chair while I twist the other one up. If you start getting kinks then you twisted too much. You don't have to do it that much at all, too much will hurt the string, especially if you twist until you start to get kinks.
Make sure both bundles are next to each other after twist a bit...
Now I twist them both back together in the same direction so they wrap around each other. It should take a bit of extra twisting to get em nice and wrapped around each other. It is very important to pull tight when doing this so there are no kinks or anything. Should look something like this:
(told you I like em twisted up more than usually,
) Ok, I don't do the hitch knot on string like this, I only do loops. Here is how I do the loop. First, after measuring your string (most strings should be around 3" shorter than the what the bow measures nock to nock, if anyone wants to know), loop it around like so...
Unwrap the extra tail of the loop.
Now unwrap a couple inches of the string under the loop to be,
Now, here is something important. You wanna wrap the the two tail pieces around the two separate bundles, but you have to wrap em in the right direction. Look at the main string and note at what direction the bundles wrap themselves around each other. You want to wrap the tails in the
opposite direction the main string wraps, or else it won't work. Wrap the first tail.
Then the other one...
After that just twist them back together. Pull the tails tight, twist it tight, and cut the tails if you want. Also, everyone seems to like to taper the tails, by letting one pop out before the other one to make the transition less drastic.