This is how I braid my own hair, and other peoples hair (All-be-it I do it MUCH better on other people's heads!):
Step 1 - Get your KK or Synthetic hair and separate it.
Step 2 - Section off a square of hair. at most 1cm x 1cm, depends on how thick you want your braids and coverage.

Step 3 - Take a piece of you Synthetic hair and place it under a piece of your sectioned natural hair.

Step 4 - Loop the KK around your natural hair tightly (better than in the pic) and push the KK as close to your head, and as centred in the square as you can.

Step 5 - Braid! Braid gently, keeping the KK tight and close to your head (make sure the braid doesn't slip down), for about 2cm. Then, with your natural hair in the middle of the 2 KK strands, take a 1/4 of both KK strands and merge them with your natural hair strand. You may want to separate your natural hair into more strands, but my hair is fine this way.

Step 6 - Braid some more! braid all the way down until you run out of hair, or to your desired length. Make sure that you DON'T PULL when you're braiding - as if you pull too much, the braid will slip from your head. Be a gentle braider. Once at the end, tie up the braid at the bottom with a rubber band.


Step 7 - Cut & melt. Use your scissors the snip off the end of the hair just above the rubber band. Then, carefully, use a lighter to melt the end of the hair, and squish it quickly with your fingers so that the braid won't come undone!
This is the end of my tutorial, and I hope someone finds it useful!
You can box braid the top of the hair for about an inch, then braid normally, but I'm only one person and then it would take me forever!!!