Dissociation is the practice of "letting go" of your physical body, thoughts & other senses. Doing so can result in much more relaxed and focused meditation, much better visualization, along with easier dream induction via WILD or similar means.

You can dissociate pretty much any time you'd like, provided you are in a comfortable position and with minimal or no outside disturbances (Auditory, etc...), it is preferable to keep your eyes closed while dissociating.

For all of these methods, start by going into a comfortable position (If you're unsure, just do the corpse position, lie on your back, arms lying down on the sides, no crossing of the legs). Then close your eyes and begin some meditation at first, simply focus on your breathing for a few minutes.

When you feel relaxed, begin to slowly ignore your body in an incremental manner, first your toes, then feet, legs, hands, arms, chest, torso and finally head. If you keep focus on your breathing at all times, you'll find that it becomes much easier to dissociate.

If on purpose ignoring a certain part of your body doesn't make sense, that's alright. Not everyone can do that easily. Try one of the following two alternatives instead.

If dissociating through simply ignoring your body doesn't quite do the trick or takes a long time, you can try this method instead which may provide better results.

When you feel relaxed, begin to focus on your body (Stay aware of your breathing nonetheless) and "amplify" the feeling of your body, feel absolutely everything of your body, do that for a few minutes. Then just suddenly ignore your body, shift your focus to solely your breathing only and dissociation will carry out very fast.

When you feel relaxed, begin to focus on your body (Stay aware of your breathing nonetheless) and "amplify" the feeling of your body, feel absolutely everything of your body, do that for a few minutes. Then pretend that this body is in fact your new body, a body that is different from the real physical one and continue amplifying it as long as you wish, the more you do it, the more dissociation.

The most straightforward way to create the feeling of that body being different is to, well, feel it. Convince yourself that this new body you're in isn't the one you had just a few minutes ago. For possibly more effective dissociation, create the illusion that your new body has more features (e.g different body shape, wings, etc...)

Dissociation from your thoughts is rather easy, this is just simple meditation in the end. Focus on your breathing, keep track whenever your breathe in or out. You cannot block thoughts or emotions, but doing so will put them in the background, you acknowledge them, but you let them pass, you don't get stuck on a specific thought.

Done in conjunction of physical body dissociation, this is possibly the most powerful form of dissociation, it will very quickly lead to very vivid hypnagogia and possibly dreams.

This is going to sound quite weird, but in a nutshell what you want to do is to "visualize visualization" and you want to keep going down this path as much as you can. So in the end you may "visualize visualizing visualization" and so on... Don't worry too much about what this means or the details, just try to do whatever feels right.

What you can do for extra focus & relaxedness, you can perform the 4-7-8 breathing technique which is explained by this awesome man!

It helps you focus, it helps you relax, it helps you sleep faster, it relieves anxiety and you can get quite euphoric from it.