Would have been better if I had a thicker cord, and better charms (myfav bead shop in Bath has unfortunetly shut down, and the other is ridiculously expensive)
Original version here:
Cut the cord in 3 equal lengths, I made mine about 1m50 long.
Tie in a knot and start braiding
About 10cm down add the first charm and continue braiding
Repeat step 2 until you have finished braiding the cord.