It comes natural to you at some point in your life. I had to try just about everything there was out there with a label "spiritual". When you find the right one, its not the mind that tells you that this is right for you but your whole being.
What happens? Ill tell you from my experience. As i meditated my body started to vibrate, it was a strange feeling, as if something was trying to detach from this dense body. As i mentioned in a post above the first one was horrifying and lasted no more than 2 seconds. But such are things with all new experiences. In my experience when i project everything becomes alive, nothings looks like the way you see it right now. You see everything is just energy going at a different wavelength. In my first few i just flew around my house, which is amusing as hell let me tell you. I decided that i have the balls to take it outside, i wasn't comfortable leaving my body and stray away. I did it anyways, i went outside and starred at street lights as if i never saw them before. It was energy emitting even more energy. I watched them for god knows how long. Time doesn't flow the same way and getting used to it was probably the hardest thing. I dont know if i can quite explain it, but when you dont observe things time doesn't exist. I see many many different entities which usually dont even care if your there or not, they just are there and the next moment they are not. Few times some came up to me and checked me out, there were no faces but you still know that they are "watching" you. I have never had conversations with anything or anyone while projecting. Words become meaningless, you do it all with emotions and feeling. Fun part is manifesting things. Whatever comes to your mind it instantly becomes reality. I let my material ego have some fun and it imagined a mountain of money, sports cars, castles and 1000s and 1000s of hot women there just for me.
Umbilical chord? Well not quite. There is no line connecting you and your body that you could see only a conscious connection with your body thru-out the whole thing. Maybe some people do see a line, i dont. I never gained any special knowledge from my travels except one. You see that there are many many plains on which things can exist and to experience them you have to match the wavelength they are on. It took me nearly a year of conscious practicing before the first signs appeared that something is about to happen. I now do it regularly, just for the fun of it. True insights came from self inquiry but thats a whole another story.