Hello. Let's talk about telepathy.
To understand this skill, we must first understand the structure of the incarnate being. To understand this, we must realize the structure of reality.
The reality from which our consciousness is projected onto the physical plane does not represent spacetime as an ordered sequence, but a continuum in the form of a plane of possibilities (hyperplane consisting of physical dimensions, time and probability space).
This is where discarnate beings, including the dead, exist. In such a place (or rather, state), communication is simply the direct perception of information. To say something is to embody it, deception involves self-deception and distance to others is measured in degree of similarity, not of spatial position. In this state, thoughts are things, beings and places.
However, for such a being to operate in the physical plane we know, an adaptation is necessary. First of all, a limitation of perception in order to operate in ordered spacetime, perceiving only one manifest set of probabilities at a time. This involves a necessary separation and the existence of what we commonly call "the mind" or "conscious mind". Second, most of the data that constitutes this being must be left out at any given time, still residing outside of spacetime, in the form of what is known as "the subconscious". Just as the sea of the non-incarnated plane, the subconscious does not operate in terms of space nor time, but rather on association and similarity of concepts. And just as non-incarnated beings, our subconsciouses can communicate with each other as well as other beings (and in fact, it does so constantly).
The average human being is like a puppet, making up explanations after the fact for decisions that are actually relayed from the subconscious. This is why, as you might know, access and interaction with the subconscious is the key to reality manipulation.
And learning to dive into it and interact with it through the use of imagination is the key to telepathy.
I hope this crude diagram I made will help illustrate my point.