It's a must read and full of great advice even if being a critic isn't your personal end goal.
Don't fall into the trap, see movies in cinemas whenever you can.
First off, this job is not nearly as glamorous for most of us as you probably think it is. That's not a complaint because I love what I do and count myself lucky to make my living doing it. But the only real reason to dedicate yourself to film criticism is because you love, love, love movies and want to spend your days and nights watching and discussing them, sometimes with a public that will be downright outraged by what you have to say. If you're still interested, my advice is write everyday whether someone is paying you to or not, and as Conan O'Brien said in his farewell speech on The Tonight Show, If you work really hard and you're kind, amazing things will happen.
This is probably generic, but it's generic because it's true, dammit: watch everything, read everyone, and then get out of the house and live a full life. The finest criticism isn't written in a bubble where the critic can only compare Movie A to Movies B and C. You have to step away from the screen and learn about sports, politics, science and sociology -- and, most importantly, yourself. Want a more practical pro-tip? Strunk & White.
You want to be a critic? Everyone can be a critic now so write. Stop talking about writing and plunge in and write. Start a blog and write about each film that you've seen. Just like I hear many people talk about wanting to learn a dance like the Argentine tango, too often they are all talk. There is nothing really stopping them from taking an Argentine tango class, at least not in Los Angeles. Likewise, in today's Internet age, there's nothing to prevent someone from writing and getting people to read your commentary. Don't do write for fame or money. Write because you have something to say and you love movies.
Read. You aren't an island. You don't exist in a vacuum. Read what other people write. Find an established film critic whose writing interests you and read that person's reviews regularly. You don't necessarily want to find someone with whom you always agree with.
Don't be mean or unnecessarily snarky. While I did at one point admire the queen of mean, Dorothy Parker, I rethought that when I considered her life and wondered if it would be wise to model mine after hers. Likewise, many of the critics I knew at one point were single, bitter, or argumentative and lived unhealthy lifestyles. So lastly, I would advise: Get out of your house, get out of the dark of the theater, and experience life. Don't use movies, video games, or theater to live life vicariously. Movies should not be a substitute for participating in the world around you. You never know where life will take you or the opportunities that might open up, so write every week but also don't forget to be an actor on the stage of life every day.
1. Don't. Just kidding. Or not! Run for the hills!
2. Read as much as you can by critics that have come before you. Lay the groundwork. Educate yourself.
3. Develop your own voice, and don't be afraid to express your opinions. If they're fully developed and thought out, it doesn't matter if you're the only person who liked a movie. Stand your ground.
4. Be willing to revisit your opinions on movies at a later date. Don't be afraid to say you were wrong.
5. Don't feel pressured to write in a certain way to be taken seriously.
6. Develop a thick skin.
7. It's easy to write off bad movies before you even go in, but you may be surprised. Try and be open.
8. Avoid trailers.
9. Work with editors whom you trust. A great editor -- especially one who is kind enough to take the time to offer feedback -- is invaluable. Everyone needs to be edited.
10. You need new and different stimuli or you will get burned out. Talk a walk around the park, read a book, have conversations about things other than movies, and find other things to do that don't include sitting in the dark staring at a screen.
(This is all advice I can certainly use myself. As most advice is.)
I've got two pieces of advice. The first one is to work out a plan where your main source of income is from something else but writing about film. It's getting harder and harder, journalists are being laid off every week and film critics are not the last one to go when they need to cut the costs. If you want to be a film critic, become one. But be realistic about it and count on that it will be a hobby. My second is a request: please don't let your readers and viewers suffer from your own fatigue and bitterness. I've seen too many critics getting less and less enthusiastic about movies overall as they get older. And I can't help thinking that it's not an effect of movies getting worse as much as it is a sign of that they've grown tired of their job and need to move on to something that still can spark their interest -- or at least have a long break. Think about the readers, listeners and viewers! They are not there to be your therapists. They're there to be enlightened, provoked, and entertained. Keep an eye open for any sign of bitterness and deal with it before it grows out of proportion.
There are many things, but the most important: do some serious soul searching about why you want to do it and whether it can even give you the life you want to lead. It's a world with little pay and no job security, where even reputable critics struggle to hold a gig for more than a year or two.