From The Awl’s advice column:

I have several friends (mostly unemployed writers) who talk about the same thing over and over: namely, that they’re not successful and don’t know people who will help them, and yet don’t do anything to change it… they go on and on about how rude it is for people not to respond to them or they are scared to send out their material too soon or since high school they’ve had insecurity complexes. 

The reply: 

Dude, I hear you. I listen to more people going on and on about the frustrations of being a writer than I listen to anything else…

So this is something you’ll want to tell these writer friends in order to shut down their sad donkey eyes and their quiet mewling. You’ll want to tell them to take full responsibility for themselves and move the fuck forward. You’ll want to say that no big break is going to make it easier to get up in the morning and write. What makes it easier is trusting your own instincts and noticing that you have giant ideas percolating in that herd-animal brain of yours, you just have to dig in and find them. After you find them, you have to write something terrible that eventually, through a lot of editing, over and over and over, becomes something great… 

Put the phone down and ask myself who in the whole wide world is supposed to take responsibility for what I write if I won’t do it myself. And sometimes, in order to take total, true creative responsibility, you have to shut people out for a while. You have to stop walking around like a giant fucking question mark. You have to stop looking for reassurance from half-interested friends, and you have to stop asking other people to help you shape your work from start to finish. Calm the fuck down and get back to work. 

This is how you get a writer to shut up: You say “Shut up.” Anything less than that, and the writer will keep talking until the sun falls out of the sky. Say, “Shut up. Go finish your shit and then edit it again and again and again until it’s great. When you’re done, then we can talk some more.”