Most artists use reference. For me, I find it most effective when I use it toward the end after the composition is in place, just to add those details that make a scene that much more believable.
These ink drawings were done in the opposite way of my working method (I think its good practice to shake things up every now and then). I would use a reference shot as a starting point, and then let my imagination take over. They're a fun exercise and I recommend it to everyone out there!
Here a photo of old buildings was my first step. After that I imagined a street scene where 2 corrupt cops were searching for a felon in some future dystopian world.
Some fashion photo was the jumping point here. Fashion has a lot of great photography, and I am always inspired by their colour usage!