I posted about this back in 08, but I figured I'd tackle it again since I had a few interviews for these kinds of jobs last year.
I have heard of a few people getting jobs via cold calls - and I commend your boldness. I definitely can't recommend this as your only route, but if you have the stomach for it (and can find the right numbers), go ahead and try. My advice would just be to be very brief and polite, don't stutter, and sound like you understand how Hollywood works. As someone who has had to field cold calls (albeit for representation), I was always happy to talk to people who were polite and succinct, and who understood that I was a human being who did not exist to make their dreams come true.
Also, don't discount pilots. They're often very short-term gigs, but if picked up they can lead to more. I would imagine they probably look to fill positions very quickly. (Feel free to comment if you've worked on a pilot.)
I know that nobody really wants to hear this, but these jobs are all filled through word-of-mouth and knowing people. The only way I landed writers assistant (and writers PA) interviews was by having friends and colleagues e-mail the postings to me. The kinds of people who might know about these openings include:
- fellow writers assistants, script coordinators or writers PAs
- other assistants who work on the show (set PA, line producer asst, etc.)
- showrunner or executive producer assistants
- the writers themselves
- assistants or executives at studios
- assistants or executives at networks
- assistants or executives at production companies
- agents of showrunners, and their assistants
- managers of showrunners, and their assistants
The other piece of advice I think is important is that people RARELY find writers assistant jobs as their first jobs. You might have better luck working as an on-set PA, agent assistant (but focus on agents who represent big showrunners), etc. Loyalty and good work sometimes does get rewarded in Hollywood; I was passed over for writers asst gigs a few times because other people had gotten promoted on the show. It's also important to let people know about your writing aspirations - after you've gotten to know everyone and proved that you're solid in your current position. You don't want to look like you're a selfish ladder-climber, but you also don't want people to pass you over because they had no idea you were interested in writers office jobs. You have to be your own biggest advocate.
Again, there is no job that will absolutely lead to a writer's assistant job (and no guarantee that being a WA will get you staffed). Some people get stuck in PA-land for years. But you might as well position yourself so that you can hear about as many of these jobs as possible.
If you're thinking that you don't know any of the people on the above list, consider doing an internship. I did four. Maybe you can even call up a show and ask to be their intern (I had some friends in college who interned on shows). If you're out of college it can be harder to find a place that doesn't require credit, but I know that not everywhere does.
Good luck, everyone! I know it's tough. Don't get discouraged if it doesn't happen for you this season. There is massive competition for these jobs, and it doesn't mean there's anything wrong with you. You might have to alter your plan a little (I certainly did).