>>2849264So you've never done it then?
Models flake constantly. Agency, off the street, professional, amateur. Constantly. In my experience (I'm not a pro, but I've shot with over 50 girls now) people you meet on the street show up more often than low level "pro" models. Most are worried about making a stranger upset by flaking. The low level local models all think they're hot-shit because they're models, and will blow things off left and right.
For a beginner who's just trying to get some faces through the camera, people off the street are just fine. They don't know how to pose, but you don't know what you're doing anyways, so it doesn't matter. Once you start to get a handle on your lighting, and how to actually put a scene together, and how to actually talk to a person you're trying to shoot, then you start working with actual models (who expect to be paid) to build a portfolio.