As the word implies, "grounding" is working with the ground in one way or the other.
Grounding is the process whereby we do two things: (1) we first use earth energy to balance ourselves, and (2) we use grounding to clear unwanted aspects from our energy. Grounding is one of the few things that really can't be achieved intellectually. It is purely a function of doing; there is no other way to get "grounded."
Water can take you where you want to go. The sound of moving water, whether it is a drip, or a flowing river is a powerful natural force for movement and trance.
Water on our planet connects everything; we ourselves are eighty five percent water. It is just an issue of allowing it to fill your awareness and giving yourself to its movement; of opening your own energy to connect with energies outside yourself - connecting the water in you to the larger waters.
There is a core in human energy, a nugget, a place where we know the essence of will, power, and intent - the place where it connects us to all creation. This is the place you're moving towards.
We are always faced with the prospect of understanding ourselves with a tool that is, at best, counter intuitive, and, at worst, a manipulating task master.
Yet here we are.
Shadow work would best be done outside, but it isn't necessary. You can do this work inside just as well.
The object here is to draw out the left side during wakefulness. Get a comfortable spot with the lights off, or only one soft one, on somewhere that will create shadows, deep shadows that run all the way to blackness in the room.