The photographers have more opportunity to achieve familiarity with the environment, but do not necessarily feel relaxed when dealing with subjects. Although this is very much a personal matter, it is an important part of photographic technique. As much as possible should also be done to encourage a subject or model to relax.
People from all walks of life generally appreciate firm but considerate direction, and an understanding of what is expected of them. Aim to minimize the time spent adjusting equipment, and project confidence wherever possible. Music can help to ease tension and fill gaps in the conversation. Safety, warmth, drinks and the normal considerations of comfort should also be incorporated into studio management. Models, professional or otherwise, will be more familiar with working procedures but still need privacy, changing facilities and somewhere to relax.
Amateur models can be found by placing an advertisement in a shop window, newspaper or magazine. Also make your interest known at local photographic clubs, college art departments, dance or drama groups and other similar organizations. People who have been trained to perform often make interesting subjects.
Another approach is to print cards giving your name and contact information. These can be distributed locally and even handed to strangers in the street. Explain that you are a photographer working on a particular project, and that you are looking for models or subjects. Don't expect an immediate answer, and don't ask a second time - just leave your card and move on before embarrassment sets in. If those you meet want to make contact they will do so.
People are often flattered by your interest in them, but make sure they understand your real motives. A hidden agenda always leads to problems. If your interest is based upon making money, declare it. If you want to photograph a girl in a bikini because you think she has a beautiful face and a perfect figure, then be honest about it. If you intend sending the images to a magazine, explain this to her and ask her to sign a model release form. If she is under 18 seek the permission of a parent or guardian. It's not fair to do otherwise. If you are planning to photograph children, arrange for a parent to be present.