Hey, check this out:
A new workshop from @carriecuinn,
Beginning November 15, 2014 – “Better Writing Through Brevity: Writing/Editing Microfiction and Flash”
From the site, "...read, write, critique, and edit short fiction of various lengths, including 140 characters, 1 sentence, 150 words, six sentences, under 500 words, under 1000. Previous students of this class have sold their final pieces to semi- and pro-rate SFF markets."
Carrie is a longtime writer / editor of speculative fiction and founded Dagan Books a SF/F publisher.
Full disclosure, I read slush at Dagan. But, really, have I steered you wrong yet?