Let's say that you have a specific condition that needs a very general but not lengthy discussion so that everybody (particularly me) feels comfortable about what might happen during a session. If after your initial communications about time, price, and general interests and things seem to being to be going well, do you leave things vague and just ask for a phone call to discuss something. Or do you say exactly what it is but that it would be more efficient to talk on the phone because he might have more questions about the situation. To wait and not say anything about the situation until the session itself I would think would be the least preferable because you might spend the first part of the session discussing the circumstances and not get down to the real fun.