When I was in grad school, I had to TA lab classes.  I discovered I really liked to teach.  I also learned a lot through teaching the material.  When I had to take comprehensive exams, one of the ways I studied was to prepare "lectures" then lock myself in an unused classroom to explain the material.  It worked.

It's the same for knitting.  You learn a lot when you teach knitting.  Perhaps there's another way to explain or think about a particular technique.  Sometimes a discussion can arise about why a slip 1, k2tog, psso is preferred over a slip 2, k 1, psso in that instance.  As a designer, it helps me to see where people struggle with the way a pattern is written.  I can think about ways to write my patterns as effectively as I can.

I started a new class at my LYS last weekend.  I'm teaching a class for my Cala Shawl.  It's more than just a project-driven class.  I teach techniques as well, particularly when it comes to knitting lace. 

If you noticed that pale yellow project on the table, it's my next shawl design.  It's off to one of my test knitters now.