A release is an excellent idea for another reason. It makes clear to the "model" that their image may be used commercially/shared publicly.
A "professional" model will understand that and be aware of the consequences to them. Someone who isn't knowledgeable about the use of photographs might not have thought it through.
It is much, much better to have someone change their mind about you photographing them before you take a photograph than to have them upset and angry afterwards.