If a client is referred by another satisfied client, then you have a bit more leeway. There will be somebody pushing from the other end, relating success stories and so forth. That helps.
If a client just comes in from having seen an ad, just to see what you are about, then it is more critical that you get somewhere in the first session.
Let me clarify right away that it is not necessary that you resolve a large portion of the person's issues in the first session. What is important is that you make her feel good and that you instill confidence. If you also handle something, all the better.
Don't waste time giving thorough explanations of what processing really is. Very few people need that. They usually forget most of it again after the first visit. The best you can do is to put them in session, let them realize that you are there for them, and that things can be improved.
Also, if you explain things too well, it is likely to act as a completion, as an end in itself. They say "Oh, that's what it is. Thank you, good bye." You are better off leaving them a bit in a mystery about what this is, and then just do it.
Don't explain the principles of processing beyond something simple like: "I ask you questions, and we find out what is going on in your mind, and then we change it."
You can refer to people or subjects if she needs references. You can say "Clearing was first mentioned by Alfred Korzybsky who developed General Semantics in the '30s". Or you can throw out some other subject that you know of that is related. "Neuro-Linguistic Programming" is a good one, it sounds impressive. If the client offers some subjects, leave her with the impression that transformational processing is both similar and different.
You never lie to a client, you are honest about what you do. But you don't have to give her long theoretical dissertations. Processing is not theory, processing is what you actually do. It is more honest to do it with her, than it is to explain its development.
You don't want either to contaminate her mind by convincing her of your theories before you find out how she actually works. There is a unique individual sitting in front of you, let's give her a chance of being the way she is.
We assume that the person has come on her own determinism. If she hasn't, find out if she somehow anyway has something she wants to work on. If not, thank her for coming and tell her to come back when she feels that she needs to.
Most people will walk in with a reason for coming. If you can bring that up and address it right away, you are in business. She will be naturally involved in the process and you don't have to explain anything. It can be as simple as:
F: "Hello, I am Flemming, have a seat."
C: "Hello. Thank you"
F: "So, what can I help you with?"
C: "I have this problem with depression."
F: "How are you being depressed?"
and we are already into a process.
Get their attention inside on what they want to change, as quickly as possible. So, if they don't already have attention on something they need to change, ask some questions that will bring it out. Keep going until you get something.
F: "So, what are you here for?"
C: "Well, I just wanted to find out what this Processing is"
F: "OK, do you have something you want changed?"
C: "What do you mean - changed?"
F: "Well, should something be different in your life?"
C: "I'd like to not get so angry"
F: "Tell me when you get angry"
If instead you had started to give a lecture on processing principles you would be on much more shaky ground. We would much rather do something for her.
The most likely process I will get into in a first session is polarity integration. One reason is because what people have to complain about in themselves usually is a polarity. One side doesn't like what the other one is doing. Another reason is because polarity integration seems to work on just about anybody, with almost no explanation. And it is not an intellectual thing, it is hard for the person to sabotage it. You usually finish it in one session with a nice complete result.
Another likely thing I might do in a first session is creative changing of perceptions. That is, simply making the client realize that she has pictures and sounds and feelings in her mind, and that she can change them. That would be when she claims to be the effect of something she is obviously doing herself. For example:
C: "I am always critical of myself"
F: "You mean, you talk to yourself?"
C: "Eh.. yes"
F: "Where does the voice come from?"
C: "Come from?"
F: "Yes, is it inside your head, or, what direction does it come from?"
C: "Hm .. from behind, I think"
F: "Is it in your own voice or is it somebody else's?"
C: "Sounds like my mother, actually"
F: "OK. What is the voice saying?"
C: "You can't ever do anything right!" (in an accusing tone)
F: "OK. Move her up front"
C: "You mean, move the voice?"
F: "Yes, move it up front"
C: "OK, it is in the front"
F: "Good, now make it speak very quickly"
F: "And move it out in the distance, so you can't hear it."
F: "What would you rather have the voice say?"
C: "You really know what you are doing!"
F: "OK, bring back the voice and have it say it so you really believe it"
F: "And then move it to the back of you"
C: "OK, yes that feels much better" (smile, pink skin tone)
Showing her that she can be cause makes a big difference. Just demonstrating that she can feel different by moving pictures or sounds around and changing their qualities can be quite a deep revelation for many people.
When you have gotten a good result on something she brought up you might end the session with a small explanation of what went on. Just to make her understand that you did it intentionally and there are principles behind what is going on. Also, if she understands the idea, she can better use the principle herself later. But notice that the explanation is much more useful and effective AFTER she has experienced what it is really about.
Finally just ask her when she wants to come back and schedule her for her next session.