Every writer will tell you that the essence of good writing is hacking, hacking, hacking your beloved pieces to pieces.
A general rule of thumb is that you should be leaving about half of your words on the cutting room floor.
Nothing forces you to distill like Twitter. 140 characters is plenty of space to put a complete and developed thought out there, but there is room for precious little else.
This is particularly true for me because I mostly tweet for the art of it: my tweets exist to amuse. A lot of people use Twitter as a source of gaining and sharing information. I use it it for myself in that way--I do a lot of gaining info, but very little giving.
I am using the Buffer app to crank out three tweets a day. I can throw them into the Buffer "hopper" as they occur to me, and then the tweets will go out at the scheduled times.
So I was combing through some of my old notes, and I am across a piece that was about 80 characters too long for a tweet:
"To the best of my knowledge I have never been burned in effigy, but if I were I would hope that the representation of my body was fairly accurate and not exaggerated to make me look any fatter or uglier than I already am."
So I took that, and whittled it down to this:
"When I am burned in effigy I hope the depiction is somewhat accurate and not exaggerated to make me look any fatter than I already am."
You hope that you maintained the essence of the larger collection of words, and then, if you're lucky, maybe you made it even more potent.
Whether or not the shorter version is an improvement, it is always a good thing to slim your writing down. Twitter presents this challenge, this opportunity, and I think it has made me a better writer.