So if it’s not technical prowess, then what is it? A bit cliché, I know, but it’s all about the connections.
There are a lot of really talented photographers, and there are even more photographers. I’m a photographer in Berlin. So are thousands of other people. Sure, different photographers have specific styles or types of photography in which they specialize. But there’s a ton of overlap between individual photographers that all excel in the same area/s.
(Enter the cliché)
“It’s not what you know, it’s who you know.” It’s true of many vocations, but I think especially true in the world of freelance photography. You don’t even necessarily need to know the person who’s hiring you, but it sure helps if you know a person who knows that person.
So my advice? Meet (relevant) people whenever and wherever you can, and be a nice person in the process. Don’t be afraid to make it known that you’re a photographer. That way, when someone is looking for a photographer, you can already be in the top of their mind and at least have a chance at being considered for the commission/job/project.