Also known as a Diamond Knot, or Friendship Knot, this is a common knot tied in a single cord. It can also be tied with 2 cords, as a decorative part of a larger piece.
Used to build either a key fob or lanyard, here we will use it in a key fob.
First make a loop roughly in the middle of a 4' strand. Note the top end is UNDER the strand.
If a key ring or other hardware is required, you may need to get it onto this strand first, located within the 2nd loop.
Make another loop to the left, going OVER itself then UNDER the strand.
Now take the 1st loop you made and slide it over the 2nd loop about 1/2 way.
Take the 1st strand and weave it OVER then UNDER 2 strands of this arrangement.
It should be OVER 2 strands on the way out.
Now bring that strand around and come UP UNDERNEATH and out through the square hole in the middle of the knot. Snug it up a bit, but do not pull tight.
If you look closely at the knot you will see that it is a loose Carrick Knot.
With the other strand, bring it UNDER this one, and around, then weave it UP through the same square hole as the other strand. Snug it up as well.
This is now a loose Lanyard Knot or Diamond Knot.
Gently snug up each strand, one at-a-time. You may have to gently roll the knot around as you do this.
Don't tighten it up all the way yet - there may need to be some adjusting.
Depending on where you started the knot, your 2 ends may not be the same length. Or your loop may be too large - we only need about a 1" loop for a key ring.
If the loop is too large, find where 1 of the strands goes into the knot. They should both go DOWN through the middle of the knot.
Pick one, and tug about 1" of the loop through the knot. Then carefully follow this strand, and pull that 1" in the same direction around the knot. Snug it up a bit. You have to 'walk' that 1" all the way around the knot, until you come out of the knot.
This is a very TEDIOUS process, so be PATIENT. And keep your eye on the strand you are following - it is very easy to get 'lost' and start tugging on the wrong strand. We don't want any distractions at this time.
Once you have the loop adjusted to the right size, now you may have 1 strand longer than the other. If so, another 'walk' through the knot is required.
With the longest strand, find where it comes out the TOP of the knot. Again this will be in the middle of the knot, at the top. Make sure you have the right strand (longest) by tugging it from the top. Only work with about 1" at a time, and BE PATIENT.
When you have it the way you want, with about 3-4' of cord (both strands), you can move on to the Solomon braid, or any other project you like.