Luke Cage is September, and Iron Fist is sometime next year, my guess is spring, so around March/April. This leaves the chance of Jessica Jones Season 2 happening Fall 2017, though I think they may end up waiting until Defenders is done.
Defenders, which is Daredevil, Jones, Cage and Fist all teaming up in a TV Avengers essentially, could possibly come Fall 2017 but my guess is it will be Spring 2018. Gives lots of time to film it and get ready, and then the big Netflix team up would come just a month or two before Avengers: Infinity War, so you'd get the show team up then the movie team up right around the same time, which would be great timing wise.
Personally I am hoping for a Punisher series, and since he likely won't factor into Defenders, that would be what I'd like to see in Fall 2017. A second season of Luke Cage and Iron Fist I'd like to see them combined together rather than separate second seasons, since in the comics they are the Heroes For Hire, and are best friends/partners. Marvel have also said they doubt they go to more than two netflix shows per year. So my ideal release schedule if I was the one in charge would be:
Luke Cage: Fall 2016
Iron Fist: Spring 2017
Punisher: Fall 2017
Defenders: Spring 2018
Jessica Jones 2: Fall 2018
Daredevil 3: Spring 2019
Heroes For Hire: Fall 2019
That is what I'd love. Then in 2020 I'd do their next phase. Introduce some new characters. I want shows for Moon Knight, Blade and Cloak and Dagger very much.