This is like one of those weird esoteric concepts, when you explain it, it can be explained in many ways. Despite all the different categorizations of spirits, it is actually supposed to be considered a category in itself.
Thought forms can be known as spiritual larva, because it doesn't have any intelligence. The provider that thought of the spiritual larva is and was the intelligence. A thought form, is a spiritual thought, literally, and once forgotten, it drifts off. That is why some people believe telepathy is possible.
People actually practice sending thoughts to each other, just to master or try to master some sort of proficiency. That is why visualization is key, because when these people do this, and it doesn't matter how far away a person is, they just have to think of the person and visualize a projection going to that person, particularly to their personal space near their head.
The interesting thing about thought forms, it is said to have a universal language, so I can imagine you can just send a psi-ball to someone and anything past that, I don't know.
Once in a while, I can hear what some people have said in their head, but I don't know if that exactly counts as telepathy. But I think it only counts through the senses that you know what a person is thinking, that just may count as telepathy. So I guess it is just being able to speak to a person without actually talking.
On last thing, it is said that thought forms, that we create when we think, can expand and expand. So they naturally build upon themselves the more we think about a particular thought. With that said, it is truly a detrimental thing to dwell on negative thoughts. And with that said, I suppose you can instill a thought into or to someone. I once knew a couple that were into the craft, who were telepathic with each other, and used to telepathically tell each other to start the car, whenever one of them needed a ride home. How do I know this is or was true? They were good friends with my parents and my parents don't naturally succumb to believing those sort of things.
I've notice one significant thing about opening your spiritual senses, is that your senses are like any other talent, so you practice.
Now, I wonder if I dwell on the fact or belief that telepathy is really possible and that I am telepathic, I wonder if that thought form can kind of engulf my very influential essence, so it can help me become telepathic. Gosh, I am telling you belief is really everything, in this case. Gosh, that was a weird thought.