Great question. Jay Earley's approach is to have people apply "classic IFS" to themselves. (Classic IFS = the way IFS is traditionally done with a therapist, it's what you'd learn in an IFS training.) The problem is, when we're doing parts work on our own, classic IFS alone isn't sufficient. Why? When we try this:

1. We try to contain ourselves and guide the process while we're in it. This immediately splits us away from being truly present and away from authentically accepting what arises. This gets us out of Self and into a managerial part
2. It invites in Self-Like Parts (https://seekdeeply.com/ifs-therapy-guide-6-most-common-self-like-parts-framework-blog-post/) like the IFS Enthusiast or Good Student Part. When we're blended with a Self-Like Part, there isn't space for Self
3. If we think we're in Self and we're not, our other parts are likely to mistrust us and stop the process. They might even start mistrusting IFS itself.

Ultimately, expecting ourselves to be able to do classic IFS on ourselves is a set-up for failure ... which then leads to thinking we're at fault. Or even worse, that something is inherently wrong with us that we can't get into Self.

Speaking from both clinical and personal experience here! (I used to wonder if something was wrong with my Self energy.)

Caveat: Trying "classic IFS" does work for some people for a short amount of time. But it seems that once our parts figure out what we're doing, they refuse to participate. It's very common to have initial success with doing IFS on yourself (via classic IFS) and then find that it just doesn't go anywhere. Talk about confusing and frustrating!

TL;DR: I teach people rituals to provide containment and a skillset that sidesteps this no-therapist-present problem. Jay Earley's book can be useful for learning the principles of IFS as long as you take it lightly and know something extra is needed to make IFS a lifelong self-healing tool