Low key photo

I love low key photos. You need a flash and must wait until the day is gone. Find a place where your model can sit comfortable, like an open air bar. First make an ambient shoot with about 1/160 sec exposure time, ISO 100 and your lens wide open to get a shallow depth of field. The result should be everything black except some lights you may see.
Now place your model and activate your flash. I use a remote trigger and hold the flash off camera, often a bit lower than the chin if the model. Then focus, back-button focus is helpful, and click! The model comes out of the dark!
Done ? .....Congratulation.