The Higher Bodies

[anagogy]

what sort of understandings are required to 1) access and 2) utilise these higher bodies in a consistent fashion?

I think a good first step would be to sensitize yourself to feeling nonphysical energy if you haven't already done so.

As Ra said in response to a question about healing, "To work with a powerful crystal such as you have, while unable to perceive the magnetic flux of the subtle bodies, is perhaps the same as recommending that the beginner, with saw and nail, create the Vatican."

So becoming aware of the non-physical magnetic flux would be a good first step.

After that you can experiment with the higher bodies. Learning to astral project would be a good way to familiarize yourself with the subtle body that is closest in vibration to your physical body.

I'm not a master of astral projection but I've experienced it on a few occasions. Learning to walk the edge of awake/sleep is a good way to begin in my opinion. Its a good platform to begin to feel nonphysical energy, and perceive these other bodies.