There are many ways to combine real life and scriptwriting - I have done most of them so here are my thoughts on the kinds of jobs you can get and the advantages and disadvantages of them...
We've all had a couple of these right? These are the slumming it jobs that we thought we would never do but get us through a year or two while we get some rubber on the road in our real work. These jobs can be fun, are usually more about the people than the work and provide us with some real world experiences along the way. My version was scooping ice creams and ripping tickets in a cinema or two in Melbourne while I put myself through a writing course.
The advantages were many: I got my days to myself, I got to see rafts of films for nothing and the people ranged from 'interesting' to genuinely likable and most of us were on other paths (artists, writers, designers) so then sense of community was strong.
On the down side I really was scooping ice creams, around 60 a shift. I ate too many of them. And then there was the assault, the armed robbery and the danger of picking up something on the floor that an older gentleman might have used to gratify themselves into. And the Junkies who locked themselves in the toilets. And then there's no sick pay and all that.
What to watch for: The difficulty is that how you feel about this job will revolve around how well your real work is doing. If you find yourself getting nothing made, just turned thirty and still ripping tickets it can make you feel like shit pretty quick.
Advice: Take it, but do it for a specific period (education for instance) take lots of notes as you may never meet this kind of person again in life, and enjoy it. Works best if you don't need too much in the way of money, so best done before you have a family or many possessions.
You want to write but you end up working for a literary agent as a office admin. The tactics for this one are simple - learn what you can, make contacts and then RUN A MILE. If you are not in the 'promotion line' then treat this with caution. Once you have shown the boss your writing, it's time to go. No one will respect you if you stay too long.
These are rare for writers, but really worth trying for. I had the good fortune to start life as an actor and discovered my urge to write about 5 years into a ten year stint. This worked great! I learnt a vast amount out about theatre, film and TV, got to perform other writers work (and sometimes work directly with them) and have enough time to continue to write. I just might have kept doing this had I not decided I needed to spread the wings and move to Australia.
Note that there can be not much in it between a near miss job and a complementary and you may have to start something to find out if which one it is...
So you think that maybe being a critic would be a good ting to do while you are writing? No no no! This puts you both in the wrong mindset to create AND on the wrong side of the industry. Being a full time lecturer could also fall into this category depending on how you play it.
This is the job that has nothing at all to do with your writing but has all those fairly solid things like career structure, regular money and all that. Sometimes you have no choice but take these jobs - if you are starting a family or something big like that then the advantages of not worrying about money can be great. The mistake is too stay in them forever (unless you are a poet, it seems to work for poets - William Carlos Williams and Philip Larkin come to mind). And even then it's not the job itself it's the failure to make the next step, which I'll get to below.
The trick with the real job is to do something that you are actually good at but is sufficiently different from writing that it doesn't impinge on your mind set. If you are doing something that is genuinely distasteful to you this won't work. Like the McJob good people help here as does setting yourself a time-limit.
The trap with the real job is that MOST PEOPLE STAY THERE. It's too comfortable and, hey, you weren't getting any work on anyway so what's the point in fighting right? Then you get a mortgage and wake up when you are 40 or 50 and you are screaming (on the inside) so you go out and buy a new car... it's the consumer trap that you swore you would never get into.
So don't get into it! Sure, do the job, buy do it on your terms, take the child care vouchers and the sick pay, use it all to the max, but don't start to define yourself here.
I got around this one by getting up and hour and half early and writing every morning. This really works - you are doing work (slower than you want, sure) and constantly reminding yourself what writing feels like, how good it is next to sitting in a four hour meeting with a bunch of wankers from finance/accounting/marketing/strategy/IT. I have been more productive writing in 90 minutes a day than many people I know who are 'full time' writers.
An interesting aside - a lot of writers have never had a real job and consequently know NOTHING about business and it's related issues. hile you are there watch and learn and steal business ideas relentlessly (I do this all the time and find it very useful).
If you have that real job the best thing to do when you are ready is to freelance (or 'consult') if you can. This is not so you have more time to write (initially you won't, trust me) but because the mind-set is very close to being a working writer.
As a freelancer you have to make your own work, know the market, deliver to deadlines, be entirely self-motivated and do your own accounts. As a freelance writer you have to do all that too, so why not start learning now?
The big thing with freelancing is that you can slowly change the ratio of what you are doing towards more and more writing without ever having to make a big jump. If you picked up 6 weeks work writing and you had a full time job it could prove very difficult, but a freelancer can move things around to fit. You can also claim your expenses on tax which means that going to those festivals becomes a valid and useful part of your activities. And this feels good and right. I also give myself writing mornings and then turbo charge my freelance activities into the night if needed.
You will almost certainly be working very hard indeed and to all hours of the night. Money can be a worry. You will take too much work, then too little. But on the upside you are getting yourself ready to succeed as a freelance writer - and not having to sit through those terrible meetings...