http://rebeccamezoff.blogspot.com/2012/12/james-koehlers-weft-interlock-join.html
Take a look! Rebecca did a great job with the video--it clearly shows the process.
As Rebecca says in the video, she is showing the technique done from the back of the tapestry. If you work from the front, then the process will be slightly different. Also, some of you who work from the front do this single weft interlock with wefts traveling in opposite directions, rather than with weft traveling in the same direction as Rebecca shows. All methods are equally right! It all depends on your preferred manner of working.
Here's another blog post from Rebecca with an exceptionally helpful video:
http://rebeccamezoff.blogspot.com/2012/12/making-tapestry-butterflies.html
I highly recommend a regular visit to Rebecca's blog, by the way. She does beautiful tapestries, makes wonderful photos, and shares so much about her process (as these videos show). Rebecca also teaches workshops through the country.
Rebecca's blog is found at:
http://rebeccamezoff.blogspot.com
HAPPY NEW YEAR TO ALL!
May your weaving days be long and productive throughout 2013 and many years to come!