F O B

Here begins the tutorial for the fob shown in the centre of the display. 
The mandrel used is two standard wine corks glued end to end and the core is a 25m.m. wooden bead.

The diameter of the mandrel must be greater than that of the core otherwise the bead may not go into the knot. Therefore I've wound a piece of card around the mandrel which gives it a diameter of 28m.m. and I've found this to be ideal for this size of core.
The finished covering is simply a column of 4-strand square sennit grommets woven into a doubled 3P*5B TH.

The TH is laid down so that there are no crossovers in the centre.
Place coloured pins as shown in the photo.
The arrangement, from left to right, is.....  white-green-red-yellow-blue.
Both ends are the same except that the bottom pins are offset to the right by half a bight space as for a TH with an odd number of parts.
The red push pin indicates the top of the mandrel.

 For the TH I'm using 1.4m.m white venetian blind cord as it renders easily through the 11 grommets which comprise the horizontal work. Here is the run list for the TH.

Starting at the top white pin,
DOWN  around white and green
UP  around red and yellow
DOWN  around yellow and blue
UP  over at white and around green
DOWN  over at green and around red
UP  over at yellow and around blue
DOWN over at blue and under at white
UP over at green and under at red
DOWN over at red and under at yellow
UP over at blue and under at white

This completes the first pass......

The knot is now doubled which gives 20 vertical parts of white into which the grommets can be worked.
For the grommets I'm using 1.5m.m. "Colourline" which can be obtained from ClassicMarine here in the UK. 
Cut four 2m. lengths of different colours.
Here I'm using orange, navy, green and yellow. 
Take orange up through the bottom and bring it out at the compartment above the lower green pin.
Working from right to left, go O2, U2, O2....... and finish as shown in the photo.
Similarly, bring navy up in the compartment below the top blue pin and work a 2-strand common grommet as shown, finishing as shown.
Next, turn the mandrel upside down and come up through the centre with green in the compartment shown,
(1)  Come straight down over navy and under orange.
(2)  Over two white, under navy and under two white. (working from right to left).
Repeat these two steps throughout. Make sure green goes under the standing part of orange and over the standing part of navy when these points are reached. Finish as shown coming down alongside the standing part of green.
With the yellow cord, come up through the middle in the compartment shown.

(1)  Come straight down under navy and green and over orange.
(2)  Over two white, under orange and under two white.
Repeat these two steps throughout. 
Come under the standing part of navy when you reach this point. 
You will go over both parts of orange naturally at the point where they meet. Finish with yellow similar to green and that is the grommet finished. 
Now work the grommet down to the bottom of the mandrel to make room for the other ten and take out any excess slack. When making the next one, make sure each coloured strand comes up in the same compartment as it did in the previous one. (for this particular pattern).
Continue until there are 11 grommets, working them down tightly together.

 
Then take the 4 ends out through the top, remove the pins and take out as much slack as possible from the TH while still on the mandrel.
This will hold everything together when the knot is removed from the mandrel.
Remove the knot and insert the bead.
Start tightening the white VB cord. You can do this reasonably firmly.
Having done this, take one of the coloured cords and, starting at the top, take out the excess slack all the way to the bottom.
Next, take another cord and do the same but from bottom to top.
Do the same with the other two cords, top to bottom then bottom to top.
You can now fully tighten the white cord firmly.
The coloured cords can now be tightened for the last time in the same manner as before.
It just remains now to "roll" the finished fob and add a lanyard of your choice.
The surface of this knot is particularly smooth, especially when "rolled" . 
The knot behaves well both in the making and the tightening.