Inner dialogue is a vital tool in process work, enabling us to easily and quickly communicate with parts of ourselves that may otherwise remain in the unconscious. These include child parts back to the embryo in the womb; times before conception or between lives; 'past life' aspects; and transpersonal beings and essences. Inner dialogue also allows us to communicate with the 'Higher Self' of another, and even with Deity.
The inner dialogue process begins with your resourceful and loving parental part who consciously initiates the dialogue. The inner healer communicates with either a traumatized part of the self needing help (the part most 'up'), or a part that is in a position to lend assistance to the healing work.
This communication happens between the conscious mind in the role of the resourceful, loving parental healer... and a previously unconscious part or parts. In the metaphor of the iceberg, all this takes place at the water line, through the medium of the imagination as the conduit of information between the conscious and unconscious minds.
Anchoring the part is the first step in establishing communication between you as the resourceful healer and the part that you wish to communicate with. Either a visual or kinesthetic anchor is used. A good visual anchor is an image of the part as seen in the mind's eye, for instance the physical appearance of the child or past-life aspect of Self. A good kinesthetic anchor is the feeling or emotion that the part is experiencing, as it is felt in a specific chakra or area of the body.
Visual and kinesthetic anchors are used for inner dialogue, leaving the inner auditory channel open for the dialogue itself. Every experience has aspects in all three modalities, but the easiest way to find a part is to anchor the feeling(s) and then follow them to an image, as in the regression process. Although only one anchor is necessary, two are better. Using either one or the other, or both a visual and kinesthetic representation of the part, it's surprisingly easy to conduct inner dialogue.
The second step in the process is to address either the feeling or the image, and get a response. Say "Hello" to the part, and listen-feel for the response. This kind of inner-telepathy often happens in dreams where you don't have to speak to someone, you can exchange thoughts and feelings telepathically, without words.
The third and final step is to deepen the connection by communicating in dialogue with the part or parts (examples here). In the steps for written dialogue (on the third page) are details about how to deepen the connection and get more specificity. These techniques are useful in any inner dialogue, and not limited to written dialogue.
The important point in this final step is to be able to understand fully what is being communicated. At first the answer may be too simple or sound like a platitude. Getting a deeper connection by asking follow-up questions to get more detailed and specific information is very helpful. Simply ask, "How specifically....?" And as with all the techniques in the self-healing work, the skill improves with practice, and the work becomes easier.