Instead of answering, I went through all the responses thus far and made a spreadsheet of the answers. (This is absolutely non-scientific and possibly inaccurate, plus there's no data as to how well these strategies worked, but hey, I was curious and thought maybe others might be interested too.)
I also have a list of "Other" answers that didn't fit neatly in these boxes or struck me in some way-- I'll link those next.
@sarahijackson posted about workshops and a quarterly writing magazine ( @innerworlds ) which caught my eye.
@floofpaldi does serials, which is super effective for other writers I know, too.
@CA_Hawthorne talks about completing the series as part of her strategy, which yes, I absolutely need to get on that for my own series!
@crcollins mentioned the @liminalfiction site, which I've looked at. This and other sites designed to boost authors (like IASFA etc) are a cool resource.