How to install Double-ended Dreadlocks
To put in double-ended dreads, is fairly easy, and less tension on the hair,
verses individual extensions, in my opinion.
Thanks to Kathryn for developing this awesome easy method.
In order to attach them, your hair needs to be at least 3-4 inches in length.
Otherwise you will have a tough time keeping the hair tight, and with them slipping out.
I start from the nape[back of neck], and work my way up.
That way you dont have the finished ones in your face.
They just lay off to the side.
The diagram below should help to explain the method a little better.
[1] You take a section of your hair, then put the dread underneath, with one hanging off to the side.
I stick it in my mouth, when doing them on myself.
It helps to keep the dreads tight, while braiding them in with your hair.
[2-3] Then divide the section of your hair into two, and use the dread as the third,
for a 3-way braid.
[4] Continue on down for as long as you want, or until you run out of hair, and then
tie it off with some string, thread, or little ouch-less elastic bands.

Once finished, you will have two dreads coming off the same section, with your hair braided down one side.
I recommend twisting your real hair around the dread, or braiding it down all the way.
That way, it doesn't get all nappy while the extensions are in.
How to install Single-Looped Extension Dreadlocks
You can attach looped extension dreads a couple different ways.
Again your hair will need to be at least 3-4 inches long.
As with the othe methods the diagram below should help to explain the method a little better.
[1] You take a section of your hair, pull it through the loop at the top of the dread.
[2-3] Then divide your hair into 2 strands, and use the dread, as the third,
for a 3-way braid.
[4] Continue on down for at least a few inches, or until you run out of hair.
Then tie it off with some string, thread, or little ouch-less elastic bands.
You can braid the remainder of your hair, if any, alone, or with the dread.
It all depends on how you want the ends to look.

Once finished, you should have one dread, with your hair braided down with it.
I recommend twisting your real hair around the dread, or braiding it down all the way, if if goes past the synth hair.
That way, it doesn't get all nappy while the extensions are in.