It is as the creator of spectacular, tactile and uniquely gooey visions that the Mexican film-maker Guillermo del Toro is rightly treasured. From the clammy fairytale underworld of Pan's Labyrinth to the throbbing Ovid overkill of his Hellboy movies, no one else outside David Cronenberg or Jan Svankmajer gives such good ooze. But the 46-year-old director has another life – less celebrated, though every bit as vital to him – as a producer of other people's work. Personal taste has kept him anchored largely in horror movies, such as Spanish hit The Orphanage and the forthcoming Disney chiller remake Don't Be Afraid Of The Dark. He also had a hand in the bittersweet football comedy Rudo Y Cursi, while his post as creative consultant at DreamWorks Animation has enabled him to sprinkle his magic dust over a slate that includes Megamind, Kung Fu Panda 2 and the currently-in-production Shrek spin-off Puss In Boots.

"I'm mainly interested in producing work by first- and second-time directors," says del Toro. He's in Los Angeles, where he's interrupted a breakfast meeting with Disney executives – concerning his script for a new, scary version of The Haunted Mansion – to talk about his shadow career. "When I was starting out, all I wanted was a break and it seemed the hardest thing to get. But it's so important to renew the voices in cinema, so when I meet people at conventions like Comic-Con, I try to bring them into my design team; a lot of them go on to be designers or storyboarders. The Americans have a term for it: pay it forward."

Not that del Toro's motives are exclusively altruistic: "You learn a lot from directors. In a selfish way, that's why I usually produce newcomers. These guys can do fearless stuff which reminds you that you must experiment. I used to teach film, and I always said: 'I teach because I want to learn.' I produce for the same reason."

The latest greenhorn to benefit from this stewardship is the Barcelona-born writer-director Guillem Morales. His del Toro-produced second film, Julia's Eyes, concerns a woman who loses her sight while investigating the suicide of her blind sister. Full of old-fashioned atmospheric suspense, a liberal share of "Boo!" moments, and instances of optical abuse that would have made even Buñuel wince, Julia's Eyes came to del Toro's attention at the script stage. "I'm drawn to stories about women in the horror genre," he explains. "Strong female roles, not girls running away from a mad murderer with a potato peeler."

Still, he initially refused to make the film because it was set in Britain. "The main character was written as English but she behaved like a Mediterranean. The melodrama is ratcheted up, the temperaments are heightened, people are having affairs … it's almost Almodóvar-esque. If you put it in England, it doesn't really work." He persuaded Morales to relocate the story to Spain, and roped in many of the key personnel from The Orphanage, including its bewitching lead actor, Belén Rueda. "I wanted to give the movie some continuity with The Orphanage, not so it was too obvious but as a bridge between the films. In Spain we've never had a film-making house like you had with Hammer and Amicus, or America had with AIP."

'I tell directors: I am a compass to help you reach the things you told me you wanted. I don't want to leave my imprint on your movie'

Guillermo del Toro Photograph: Chris Pizzello/Reuters

Morales himself didn't need much convincing. "There wasn't a lot of work in switching the setting," he explains. "It's not Spain in any real sense anyway; it's just a creepy place. The aesthetic of the film is based around the idea of Julia going blind. Her world isn't ugly, but it has nothing left in it that is beautiful." But Morales's intention to make Julia's Eyes resemble a faded, European version of an American video game brought him into conflict with his producer. "Guillermo loves the gothic aesthetic. Oh my God, he loves it! And I don't like it at all. But if you see your film clearly, he will respect your point of view."

For del Toro, creative tension is part of his own learning process. "We had many fights," he says. "For instance, Guillem wanted a long sequence in which you don't see the characters' faces. I said, 'You cannot pull that off!' I thought it was the error of youth. But he did it."

Fittingly for a director exploring the theme of sight and visibility, Morales says that del Toro opened his eyes to some unexploited opportunities. "The way he works is by saying: 'Why don't you try to open that door?' There's a moment in the film where there are lots of photographs, and Guillermo asked: 'What about the camera that took those pictures? Where is it? How could you use it?' I hadn't thought about that. The door was ajar and he invited me to open it."

The key to good producing, del Toro insists, is guidance. "I tell directors: 'I am a compass to help you reach the things you told me you wanted. I don't want to leave my imprint on your movie.'" Of the producers with whom del Toro has worked, he cites Pedro Almodóvar, who produced his film The Devil's Backbone, as the best. "Pedro taught me everything I know about producing. He said, 'A good producer is there when you need him but he's nowhere near when you don't.' I find my life as a producer incredibly rewarding. I think I learn more than when I'm directing; I have a clearer eye for someone else's problems than my own. Right now, I'm on deadline to deliver a rewrite of a screenplay, and I wish I had myself to show me what to do. When I'm working on other people's projects, I have an incredibly analytical mind."

That screenplay is Pacific Rim, a science-fiction movie in which the action is divided between a version of Earth terrorised by monsters, and another universe located five miles beneath the ocean. The prospect that it could start shooting this autumn is an especially tantalising one for a director who has written, budgeted and scheduled three wildly ambitious movies in the past three years, only to see each of them fall apart at the 11th hour. "I'm very eager to get beyond pre-production on something," he laughs.

A nine-month delay to the start of production on the two Hobbit pictures which del Toro had co-written forced him to vacate the director's chair last year; Peter Jackson has now begun production. "I write back and forth with Peter, and I'm following eagerly the development of the movies," del Toro says diplomatically. He received arguably an even greater knock-back two months ago, when Universal declined to finance his adaptation of HP Lovecraft's monster extravaganza At The Mountains Of Madness. Even the presence of del Toro's friend James Cameron as producer couldn't assuage the studio's fears about lavishing such a colossal budget on a disturbing, R-rated movie.

"It's incredibly frustrating," he sighs. "I love that project. I've been carrying it around with me for 13 years. But if nobody beats me to the punch on the things I want to do with the creatures and transformations and set designs, then it will happen … even if I have to shoot it with sock puppets in my back yard!"