Based on an unscientific poll of screenwriters I know, the following seem to be the biggest roadblocks:
1) You’re spreading yourself too thin with your full-time job, social life, family responsibilities and/or other interests that prevent you from finding enough quality writing time.
2) You’re working on too many scripts at once. Halfway done with this one, a third of the way with that, stuck with no third Act for another.
3) You’re so infatuated (or obsessed) with your idea that it’s turning into a creepy little Pygmalion scene or your psychotic Frankenstein monster. You just can’t let it go. You’re constantly tweaking and revising the same scenes over and over again.
4)You’re spending too much time thinking about the deal you’re convinced you’ll get or making notes about which stars to get the script to.
5)You get mad at the script, as if it’s a recalcitrant child who won’t listen.
6)You somehow expect the screenplay to fix itself.
7)You’re waiting for your Muse to do her part and you haven’t realized that she’s like that girl/guy who dumped you and left town without a forwarding address.
8)You have negative people around you who are discouraging.
9)You’re just lazy and more of a slacker than you thought.
Whichever point(s) above applies to you, there’s only way to deal with your inability to see a first draft through to the end: confront it.
It’s almost like going to therapy. You acknowledge your problem, figure out why you’re letting yourself be victimized by it, then take the necessary steps to get out from under it. Owning up to what you’re doing wrong (or not doing) is the first step.
Some problems are easier to deal with than others. If your brother or a parent or even a significant other ridicules or minimizes you for pursuing a screenwriting career, you must turn a deaf ear to the negativity. Let them carry on, smile and keep writing. It’s your dream, not theirs.
If you come to the conclusion that your biggest problem is laziness, i.e., you talk about writing a screenplay more often than you actually do it, you must give yourself a wake up call. Stop goofing off. Stop wasting time. Instead of going out drinking with your friends, shopping at the mall and doing all those things you do to avoid sitting at your computer and grinding out five more pages (even if they’re so-so) find a mirror, stare long and hard into it and remind yourself that writing screenplays isn’t a day at the beach.
It’s hard. Very hard. And it takes discipline, concentration and tenacity to finish one. In my next post, some solutions to getting around what's blocking you.