Twenty-seven years ago, when I worked with my first DID client, I became the "go to" person for soothing the young, distressed ego states. As a result, I was on-call 24/7, never took longer than a week's vacation, and was constantly fielding emergencies. Finally, a savvy consultant told me to put the "oldest, wisest part" of the client in charge of all distressed, younger, or destructive alters. What a relief! Within three sessions, the client could self-soothe, make adult decisions, and deal with new alters as they popped up. (This was a complex ritual abuse case with lots and lots of parts.) Therapy sessions became case consultions. I worked with the most adult parts of my client to create safety, internal communication between parts, internal and external boundaries, and good, safe rituals of orienting "new" parts to the present and giving them the rules. The therapy wasn't over then, it lasted 10 years, through trauma processing (which got more efficient when I learned EMDR), lots of sorting out "then" from now, the grief process about her awful losses, and coming to terms with her current life. The client still contacts me every 9 months or so for a tune-up session.
So, all of you who work with parts: If you help the oldest, wisest, most nurturing parts run the show, the client gets to do more of the work, feel effective and in charge of his or her life, self-soothe, and heal faster. If you want to communicate with younger parts, ask an adult, the adult, or the "team" to ask about or talk to the part. "Can you go inside and tell me how that 2-year-old part is doing now? . . .Can you remind her that you are always there for her so she's never alone again? . . . That she's safe now. . . And that she lives with you in your nice house. . . ."
I do ego state work with 85% of my clients and I rarely speak directly to any but the presenting adult. The only time I do, once a decade, is when I'm working with a new client, who pops into a part I don't know that's amnestic for the rest of life. (The ultimate "Oh S–t!" moment of therapy.) Then I introduce myself, if the part doesn't know, explain that we're in my office, and gather information: age, name, and what it needs, or what it does and "Did you know that you're part of John?". Then ask for "Adult client", to come back. Sometimes, with a count of three. It's always worked. If the presenting client doesn't remember the situation, I offer to set up an introduction. When I do, I refer to the presenting adult, team, etc. as the boss.
Most ego state work is much less dramatic. I often ask people to tell me how old something feels and if they can talk to that 3-year-old, 5 y.o., etc. part. Most people can do this. It doesn't take formal dissociation. For the dissociative disorders of complex PTSD, Axis 2 diagnoses, DDNOS, and DID, formal ego state work, combined with EMDR or Brainspotting or Somatic work for trauma, in conjunction with attachment-based therapies are always called for.