Those who would guide abide by those “rules” of their plane. Therefore, if their plane creates barriers between themselves and those they would guide, then must they learn to work around, through, or within those barriers. We find that our most obvious barrier is that of communication. For the methods of communication vary so between your plane and ours. Therefore, do we find it necessary to work with one fragment for many of your years, many of their life times, for the communications barrier to be overcome. For those of the astral plane who would guide others on the physical plane, is it more of a barrier for the visual perception. For they must determine what those on the physical plane would accept in terms of a visual presence. For some, is it no presence, for those being guided presume the presence to be ghost or haint. For others on the physical, is there a need to appear as one robed and with wings, for they would only accept angels. So that is the primary barrier they seek to overcome.
As to choosing how we would be contacted, is that usually within the agreement made between guide and guided. For if the agreement is that any plea, however vague, will invoke the agreement, then even a thought might do it. Once invoked, the method of communication is decided by both guide and guided, for again, must it be mutually effective for both. For the guide to determine that they will only communicate through auto-writing, yet the one they guide has limited or no use of those limbs, would be silly indeed. Therefore, is it a choice made by both, not just one.