GOING TO THE ENDING TO GET TO THE BEGINNING
Rather than start another play and half-way through come to the realization that: a) there is no ending or the ending doesn't match the rest or b) it's full of crap, I'm still in the thinking stage. Perhaps John Irving wouldn't approve but then again, I kind'a think he would.
Can't speak for others but writing a play, short or otherwise, comes easy when the idea is good and I can relate to the concept personally.
Read somewhere - can't trace down the source - that Woody Allen, director, writer etc. etc. starts his script with one word. This to me is incredible! He actually builds his script from one word. Mind you I've got ideas that worked for my mini-plays while sitting in a hair stylist chair and in my dentist's office. No matter where I am, I study and take notes. Sometimes it works and sometimes it don't but when it does, as I've written many times before, it's magic.
The more I'm writing this, the more ideas are flowing through/into my brain so I better take advantage of my muse. It could be a quick visit.