It is thought that lucets were used by the Vikings - they have certainly been around for hundreds of years. A lucet can be used to produce all sorts of useful and decorative cords and the cord-making process is quicker than most other methods, including French knitting and kumihimo. You can make a lucet from a plastic fork (just break off the centre two prongs) but this Instructable shows how to make a wooden one which is more durable and much nicer to hold. It's made from a door wedge, which are easy to find and very cheap - mine cost £1. Try to find one with a turned handle like in the photo.

You will need

A small hardwood door wedge - mine was 150mm long and 24mm wide (6" x 1")
A hand saw (optional)
A coping saw
A drill with 8mm (5/16") and 12mm (1/2") wood bits
Coarse and fine sandpaper
Wax or varnish (optional)
Pencil, ruler, rubber
Scissors and a scrap of paper

Step 1: Marking the Cut

Measure the width of the wedge and then draw a U-shaped template on the paper. The width of the U should be about 10mm (7/16") narrower than your wedge (to give prongs that are each about 4mm (3/16") wide, plus an allowance for the width of the pencil mark) and its height needs to be about 35mm (1 3/8") long but can be longer if the wedge is long enough. Cut down one side of the paper U and round the curved base, then fold it in half to make sure the other side is exactly the same (refer to photo). Cut the remaining side to end up with a template. Place it on the wedge and draw round it with a pencil. Check that the prongs are about 4-5mm (3/16") wide and adjust if necessary.

Step 2: Making the Prongs

Put a pencil mark on the centre line of the wedge 6mm (1/4") up from the base of the U. Support the wedge on a couple of pieces of scrap wood so that its centre line is approximately horizontal. There's no need to be too accurate, just judge it by eye. Drill a 12mm (1/2") hole at the marked spot to form the bottom of the U. Saw down from each side of the tip of the wedge to meet the edges of the hole. I found it easiest to use a hand saw for the initial cuts, then a coping saw with a fine blade to cut the base of the U.

Step 3: Shaping the Prong Tips and Drilling the Hole

Use the pencil to draw a rounded shape that smoothes off the top edge of the U, tapering each prong to the outer edge of the wedge (refer to photo). Remove the excess wood down to this line with coarse sandpaper.

Mark a point on the centre line of the wedge that is about 25mm (1") below the U. Support the wedge with its midline horizontal again and drill an 8mm hole right through it.

Step 4: Finishing the Lucet

Use the coarse sandpaper to round off the hard edges of the base and sides of the U a little. Smooth all the cut surfaces with the coarse paper and then the fine. Wrap sandpaper around a pencil or something like a paintbrush handle to get into the curve at the base of the U and the inside of the drilled hole. Take particular care that the tips of the prongs and the edges of the hole have no sharp edges that could catch the thread used to make cord. Remove any remaining pencil marks with a rubber.

Finally, you may want to wax or varnish the lucet.

Step 5: Cording With Your Lucet

The simplest type of lucet cord is made as follows, but I'll do another Instructable some time on making more interesting cords on a lucet.

Refer to photo 1. For a lucet of the size of this one (distance between prongs about 15mm (5/8")) choose a smooth, medium thickness thread or yarn for your first attempt, or even string. Hold the lucet in your left hand with a flat side towards you. (Reverse all these instructions if you are left handed.) Take the yarn end from the ball or reel and thread it through the hole from back to front, leaving a short length hanging down at the front that you can hold as you hold the handle.
Photo 2. Take the ball end of the yarn and bring it towards you, between the prongs, and then round the outside of the right hand prong to the back, and back between the prongs and round the outside of the left hand prong. Complete the figure of eight by bringing it through the prongs again and in front of the right hand one.
Photo 3. Keeping hold of the ball end of the yarn in your right hand to apply a little tension, use a finger (or a toothpick or bodkin if you prefer) to slip the outside of the loop that is around the right hand prong over the yarn that leads to the ball. The loop needs to be reasonably loose to enable you to do this, but it should loosen easily enough because the free end of the yarn is just dangling through the lucet hole. You will now have a new loop on the right hand prong.
Photo 4. Keeping the ball end of the yarn held to the right, and holding it in such a way that yarn can feed under gentle tension, rotate the lucet through half a turn clockwise (when viewed from above). What was the right prong is now the left one and yarn will be across the (new) right prong as before. (You will always be working on whichever prong is on the right at the time.) Give a gentle pull on this yarn to centre the beginning of the cord between the lucet's prongs (you'll find that pulling carefully will shorten the loops on both prongs, not just the right hand one), but resist the urge to try and tighten things up by pulling harder.
Photo 5. Now slip the lower loop on the right prong over the yarn above it, as in 3 above. Don’t pull the yarn, just leave a loose loop. Rotate another half turn clockwise. Before making the next loop, pull gently to the right on the front of the loop on the right prong. This will tighten up the knot that has formed in the centre and give a bigger loop that can be slipped over the yarn to make the next loop. It also creates a firm, even cord. Finally, pull the ball end of the yarn, as in 4 above, to centre the cord. If it doesn’t slip easily and tighten both loops it is probably because you pulled too hard on the front of the right hand loop and made the knot too tight, so just slacken it off a little.
Photo 6. Continue in this way: create a new loop on the right prong, rotate, pull the front of the right loop, pull on the ball end of the yarn, make a new right loop, repeat.

Pull the cord you have made through the hole every now and again to keep it out of the way, as in the final photo if this step. After a while you may want to wrap it around the handle.