the best thing to help this process along that i have found is finding a lighter that will light and stand on its own.
that way you can set it down, heat your ends with one in each hand and join them with out fumbling all over.
I just hold the two ends to be joined parallel to each other in my left hand (I'm right handed) then in my right hand use whatever lighter I have at the time and melt both pieces they quickly put down the lighter and join the two ends together.
Then I heat and reshape as needed.
I get them bubbly hot and put them together then after about 1-2 seconds quickly roll the joined ends between my thumb and forefinger. It seems to be a very strong bond compared to just pushing them together. Be careful though it's hot!!!
I have started covering the melted joint with a short piece of heat shrink tubing. Had a few joints come apart while tightening and was a pain to unravel to reconnect. Heat shrink tube has seamed to solve that issue so far.
link to manny method:
Looks good to connect two different colors but you need access to each end of both pieces of cord, wouldn't work if you run short on a long project that's already woven together or near completion.....