Okay, I think I've caught most of the major pre-construction issues that should be considered before starting a project. Onto actually making a beaded braid... (For the purposed of the rest of this post, I am talking about an 8-strand all-bead braid, with the same beads on each strand).
Beading Your Strands. This may seem a bit confusing, but while your braid will have 8 separate strands, you are really working with only four pieces of fiber. You get eight strands because you're folding four pieces of material in half, and the middle is going to be the start of the point of braiding.
Good planning is essential. Measure (more about needed length below) and cut all four strands of fiber at the same time, fold them in half and mark the center point with a marker. Roll up one side of the fiber onto a bobbin until you get to the middle, then roll up the other side. When you're adding beads, keep one side rolled up, confirm your count and write it down, then roll up the side you added beads to - and try to capture all of the beads within the bobbin before unrolling the other side. If you can't capture all of the beads, make a slip knot at the midpoint to keep the beads from floating to the wrong side. Unroll the other side and repeat. Do this on all four lenghts of fiber (8 bobbins, four pieces of thread, eight ends - get it?)
Mounting the Strands on the Disc. Try to keep all of the beads captured within the bobbins and carefully pull out any slipknots you've needed to make. At this point, pull out enough fiber so that there is a total of 6 inches between the bobbins - 3 inches on either side of the center mark. I like to start with the fibers crossed North left to South Right, South Left to North Right, East Top to West Bottom and West Top to East Bottom.
Beginning the Braid. If you haven't thought about it before, this is the time to decide how you are going to actually finish the end of the braid, because how you plan to finish will determine the best way to start. In each case, you'll be making a dozen or so passes before actually using any beads, and you also will have to attach the counterweight.
I am deeply fond of cone shaped bead caps captured by an eyepin buried in the braid, then wrapped. I was also taught to use solid caps glued onto the end of the braid. Another method calls for starting the braid around a jumpring that captures all eight strands at the point of braiding (where all threads are crossed).
The first five steps are how I start every beaded braid except when I'm using a jumpring at the poing of braiding.
1 - Get a piece of narrow (1/4 inch) ribbon, about 3 inches long. Plus a long (2.5 -3 inches to be safe), eyepin in the right metal to match your findings.
2 - Flip the "loaded" kumihimo disc over. If your disc is fresh, the slots will be nice and tight and you won't have to worry about the cords slipping out.
3 - At the point where the cords cross, capture the strands with the ribbon and made a SINGLE knot - one half of a box knot. The knot must be on the bottom - this is ESSENTIAL.
4 - With a safety pin, attach the counterweight (a drawstring jewelry pouch filled with pennies works very well) to the tail ends of the ribbon.
5 - Start braiding. I'm not going to tell you how this is done - you should know that before you start.
There are videos on YouTube if you need a refresher. Make 4 passes. By "passes" - I mean a complete movement of North to South - South to North, and turn left. Two movements of thread, not one.
Now comes the fun part - incorporating the eyepin into the braid.
6 - At the point of braiding, hook the eyepin around one strand. The pin must face downwards when you are holding the disc in the working position. Check and make certain that the eye on the eyepin is securely closed, so it doesn't fall out.
7 - Braid another 6 passes and stop. Check that the eye of the eyepin is securely capture by the braid - which should be tight and tiny at this point. If it feels insecure, braid a few more passes.
8 - If everything feels secure, flip over, unpin the counterweight bag from the ribbon and very carefully unknot and remove the ribbon from the braid. Reattach the counterweight bag by carefully putting the safety pin through the eye of the eyepin.
Now you're ready to start moving beads into the braid. I like to get about two or three inches of braided beads and then add the beadcap at the working end.
9 - Flip the loom over again and place it on a flat surface - and made sure that all of the threads are secure in their slots. Remove the counterweight bag and safety pin.
10 - Feed a beadcap on to the eyepin and do a loop and wrap (I'm not telling you how to do this either). Replace the counterweight bag by pinning it through the wire loop.
11 - Start braiding again, and keep at it until you've used up all the beads.
To finish the far side, you basically have to reverse the process. It's a little tricker to add the eyepin, which will face UP when the loom is in the working position. You're going to be braiding around the pin - like ribbons 'round the maypole this time.
Other Problems You May Encounter and One Thing You Sould NEVER EVER DO
1 - The Bead Won't Stay Tucked. This is a particular problem at the start, when tension hasn't been established. This is why I like using a counterweight bag, it creates the tension needed to keep the first few beads tucked. Sometimes though, a bead just won't stay tucked, and you may have to hold it with your thumb before crossing it with the other threads.
2 - I didn't tuck the bead, and I've made a few passes. The bead is on the inside of the braid. What do I do? This is probably the most common mistake, and in trying to fix it, the easiest way to screw up your braid. You'll need to undo the braid to the point where of the untucked bead - but you have to be CAREFUL. Undoing means you are literally "backing up" - moving your strands and recollecting beads to the bobbin in the reverse order of the braid. Unslot only one thread at a time.
Never, ever, ever remove two strands from their slots at the same time. EVER. Got it?
It's worse than crossing the streams*. It is even worse than feeding them after dark and getting them wet.**
When you take mulitple strands off, you lose the order of the braid, and it can be nearly impossible to repair. There is no way to "fake" a braid - all mistakes are visible.
In some circumstances, if you don't catch the tucking mistake until it's too late (too many inches to undo), you can use a crochet hook to bring the thread over the bead and "pop" it out. Sometimes this works, sometimes it doesn't. And sometimes, if you try to force it, you'll break the strand and then you'll have to start from scratch.
3 - I have beads left on some bobbins, and none on other. In other words, I miscounted. Is your piece long enough? Do you have any beads left? As long as the cord stays in the slot, you can unwind your bobbin and add beads at the back end. In once case, I miscounted so badly that I had a total of 46 beads on three strands and zero on the other five, so I simply redistributed them on each strand.
4 - I've run out of cord on one side, and I'm not done yet! Sorry kid, but your SOL. You can't add thread length without having a visible break in the action. You need to be careful at the start - my favorite motto is especially appropriate for kumihimo - Begin as you mean to go on. Measure twice and cut once is also somewhat relevant too.
Cord Length: I guess this would be a good time to write about how much cord you'll need. Everything is dependent upon the beads you use - bigger beads will mean you'll use more cord during each pass, and since it's not possible to add length to a working piece, you've got to plan carefully.
Frankly, I don't care about wastage - I'd rather have to throw out eight pieces of 10 inch long waste than be left with a too-short braid. Working with largish beads or pearls, I double the finished length and add a few inches for good measure. But wait - that means that each of the FOUR (not eight) pieces of cord/thread will be four times (and then some) the length of the finished necklace with you first measure and cut (because those four strands are folded in half). Seed beads mean you've got to plan for 1.5 times the finished length.
I am certain that there are other things about kumihimo and beads that I should have mentioned - but those will have to go into another post, at another time. The best thing about beads and kumihimo is that if you are willing to experiment - with your bead choices, your pattern layout, the string materials and the colors you use, you will never stop being surprised and delighted.