Amy Wimmer listed several ways to learn teaching techniques:
I have learned lots just by closely listening to
callers I like as they call.
Take notes.
Ask if you may record them.
A very valuable tool is house dances, where a small, supportive group
gathers for the purpose of learning together. (We're doing this
tonight in Seattle)
Get a small group of callers together to talk about the way they teach moves.
Look for calling workshops.
Try open mic dances.
Check out the books available through CDSS.
I'll add
Notice what other callers do at newcomers' sessions
At the dance series I help organize, our practice is to offer
callers the choice of leading the pre-dance newcomers' session
themselves or of having us supply someone to do it. Most callers
choose to lead it themselves. So by attending newcomers' sessions
at our series--or at any series with the same practice--one would
have the opportunity over a period of months to observe the ways
that a variety of callers teach contra dance basics. They'd also
get to see which things the different callers try to teach in the
newcomers' session, where there may be lots of newcomers and only
a modest number of experienced dancers to help out, and which
things they leave for later, when newcomers will be surrounded by
a much larger number of experienced dancers.
--Jim