Wired Magazine has a fascinating interview with Ridley Scott about his film career. One of the best bits is how the first three films shaped the process. I dropped the quote in directly, but I would recommend reading the full Ridley Scott interview
[E]very time you do a movie, in fact, the more experience you get, you can almost say, the less you know. Because the more you know, the more can go wrong. So that can also make you more insecure. But I guess I don't really worry about much. I just try and do the best I can on the set.
[At the time I made Blade Runner], I'm in three movies. I mean [Blade Runner] is my third movie. My first movie is pretty good actually, called The Duellists. And that was criticized for being too beautiful, and you know, I took that to heart. So the next one was Alien, and that was less beautiful but more impressive and more grungy. I was criticized for a lack of character development. I said, "What fucking character development do you need when you've got that son of a bitch on board?"
So I started getting defensive, then realized actually I was in fairly good shape in terms of being a film director, because for the kind of movies that I will do, I will be always very visual. And I won't push it in your face, but I know it's an advantage. I've got a good eye, and I don't know what a good eye means, but I've got a good eye, I think. I can align and see way beforehand, imagine way beforehand, what's going to be. That's good, that's very useful. Because some people don't have that, they [need to have] other talents.
I've had to evolve my capabilities in developing material... Alien I was sent, and I read it and thought, "I know what to do with this," and didn't want to change anything. Because they kept saying, "Want to change anything?" "Nope." They said, "No?" I said, "No. That's it. Let's go." So that was great, because that flew.
And then Blade Runner was the play, which then evolved for eight months every day. [The writer] and I and [the producer] every day talked, talked, talked, talked. As [the producer] was trying to get the financing, the film was growing. And that was interesting because that was a real evolution of working alongside a writer that I really respect. And it was hard for him because sometimes he'd say "Oh fuck." I'd suddenly have this brain wave that comes from a visual notion. We'd get a lot of, "Oh God, I thought we had that worked out." I said, "Yeah, but wouldn't this be great?" And he'd say, "Yeah, but that will mean this, this, this, and this." [And] then there's a domino effect...