Master the art of lucid dreaming! Before you are going to be able to enter the dreams of others, you will need to master the art of becoming conscious during your dreams. I prefer falling asleep conscious, but that is rather difficult for most people to master. I recommend you learn how to master the technique of programming yourself to become aware you are dreaming in advance and then realizing you are dreaming after the dream has started.
Again, I prefer just falling asleep and going into REM consciously, but it took me MANY years to master this technique.
If you still need to learn how to master the art of lucid dreaming, read this article here:
It will teach you how to do it.
Decide your target and contact them! Decide the person you want to contact in the plane of dreams and make it very clear in your mind you want to remember to contact them once you are aware in your own dream.
Once your body is asleep, your mind is awake and you know you are dreaming then you can attempt to shift into your target's dream. However, if they are not in REM this technique will fail. You can't enter someone's dream and interact with them if they are not dreaming. That's what makes this technique so difficult -- you have to be able to go lucid in dreams virtually at will, because timing it out so you are in REM at the same time they are is a tricky thing to do!
I recommend making a list of friends you want to contact, just in case, so every time you go lucid, you have a much better chance of at least catching one of them in REM at the same time you are.
Anyways, you want to know HOW to enter their dream! If they are asleep and dreaming, it is quite simple, once you become aware you are in a dream. All you do is close your eyes, say the name of the person out loud and form the image of their face in your mind behind your closed dream-eyelids and start spinning around in circles. That's right, hold your arms out to your side and spin around in circles as quickly as fast as you possibly can! When you feel like you are in their dream, feel free to stop spinning and open your eyes. You'll just know when you are near them in their dream.
Interact with your target. I am not sure what your intentions of practicing dream walking are, but they must be pretty strong if you made it to this point. Mastering the above two techniques is no easy task! It has taken me years to get it down to a science.
Interacting with the target can be the best part. You can tell them they are dreaming and try to make them become lucid. However, for some reason untrained people are VERY hard to awaken in the dream world. Many of my friends have refused to believe me in the dream world, but then the next day some of them have told me they had a 'strange dream' about me the night before. You may not want to waste your time trying to convince them they are dreaming, but if you do, simply ask them to remember how they got there. They will find that their memory is all fuzzy and they can't remember how they ended up where they are at that moment! Tell them that is because their body has fallen asleep and they are in a dream.
Personally, I prefer to do other things with my targets. You can offer them advice that will stick in their subconscious mind when they awaken. Most people don't remember their dreams, so they won't remember you telling them, but they will believe it as truth. You can basically control the minds of anyone whose dreams you can enter. I know, it sounds like some sort of weird dark art, so use it responsibly and only for the good of all involved. However, it REALLY works.
Tips and Warnings
Regardless, this article is not meant to prove that it is possible. It is for those of you who already know it's possible and want to learn HOW to do it.