The feeling we start with might come from the client as a complaint given at the start of a session. It might be what we find when we dig into what the client's complaint is. Or, it might be something that appears while we are pursuing the techniques and subjects of a general module. Or, you could also methodically search specifically for unwanted feelings.
If you are working over a general question in a module you would switch to re-experiencing if it is clear that an unwanted feeling is a central block in the subject at hand. You wouldn't necessarily switch just because the client says that she "by the way has headaches once in a while". No, but you would if you find that the subject of communication, which we are addressing, is hindered by a feeling of insecurity that she has.
If you want to search for unwanted feelings systematically, you can do it by asking for different kinds. Like, "Do you have any (pains, pressures, tenseness, nervousness, etc.)" It would be essential that you only accept feelings that are there to some extent in the present, not just stuff one remembers having had once. It is also essential that these are feelings, stuff one feels kinesthetically, not just abstract ideas.
This is an outline of the procedure for clearing incidents.
1. Start with a presently unwanted feeling.
2. Get the feeling specified precisely as to where it is and its perceptual distinctions.
3. Get the client to feel the feeling right now.
4. Demand that she lets the most basic incident appear that includes that feeling.
5. Assist her as necessary to focus scattered perceptions into an incident.
6. Get her to lightly experience the incident from beginning to end.
7. Do it again if more material is surfacing.
8. It this doesn't appear to be a core incident, find the exact trigger point, freeze the frame there, examine what goes on, and get her to hold that feeling and demand a more basic incident. Continue with the incident that surfaces.
9. If it does appear to be a core incident (a traumatic incident providing the experiential context for the feeling, rather than just a semantic context) then continue with this incident.
10. Ask what other viewpoints are available in the incident.
11. Experience the incident from any significant viewpoint. Particularly including the causative viewpoints, not just the effect viewpoints.
12. Ask for any decisions made in the incident.
13. Ask what there is to learn from that incident. There needs to be a positive learning of some kind.
14. If it doesn't turn into a positive learning experience after working it over in that manner, we can add resources to it or rewrite the script if necessary. Find out what resources would have made it work better if they were there. Have the client experience the incident the way it would be if those resources were there. Let the incident happen differently, in a more positive way, and carry the change forward. Let her visualize how things would be/would have been after that point if that is what happened. How would she have developed differently, how would she be today, how would the future be different.
15. Get her to come back to present time if she isn't already there.
16. Ground her in the present, being extroverted and aware.
17. If there is more time, have her feel how the area of the feeling feels different now.
18. Trace that new feeling to a core incident in the same manner, and clear that.
19. Repeat this loop until the feeling has either disappeared or transformed into something more useful for the client.
20. End with the client extroverted, grounded, looking towards the future.
Re-experiencing is a technique that can be used at any time, at any level. As long as it always includes multiple viewpoints and as long as it always addresses the person as cause and leaves each incident as positive experience.