Hello! Astraling is a very spiritual experience and honestly can be quite euphoric. Having the ability to detach one's astral body-soul from ones physical body is really fufilling and can bring some closer to themselves, others, and higher beings. It takes a concious mind to be able to explore and learn durring travel to different realms/dimentions. People all enter and exit the state differently. There are many types of astraling states as well as all sorts of experiences and teachings which make it the phenomenon it truly is.
Out-of-body exoeriences, such has extreme visionary medium detachement, near-death experiences and some types of seizures and disorders like epliepsy can be classified under certain conditions a shock into astral planes. Some people claim that dreaming can unlock astraling while others say you can only be awake and almost "zone" while your mind prepares to split the body with our manefesting spirit . I personally believe that either way it is possible, yet there is a clear distinction from lucid dreaming and astral projection.
As I said, everyone learns to astral differently, some methods work for some, others don't; but it is all on the individual and how they learn/react to this mystical model. For some it takes many practices, meditation, opening of the third eye, and for others it is a natural occuring instance or they can easily slip on by just doing something that triggers them. The best way is not defined because you would have to experiment yourself and find whats best fitting. All depending on your experiences and lifestyle :) .
So, as you asked, what is it like? Well majority of people can feel themselves leaving their bodies. Weather it be an extreme vibration in your limbs or fuzzy tingling from head to toe- for me its as if I am taking off in a rumbling jetplane, feeling myself go weightless. One is aware (conscious) that the seperation is in the process. Since you are aware, one needs to stay calm and accept their transition. Although many comment that their first time astraling is very intense and this can feel uncomoftable the best thing to do is remind yourself its almost natural, and a high primal experience.
Once the two is seperated, some seea silverish long cord connected to them, yet you feel perfectly comfortable, this is the etherical chord connecting the two bodies together. Others can also see their aura or a hue over their astral bodies, resembling a ghostly appearance. From there people visit "otherworlds" environments that are not recognizable, and often other dimenstional realms where times does not exist. Occasionally this seems really trippy and unerving at times, but every individual is able to have their awareness.
With the diverse surroundings, many see the things that happen in an astrals as a heavy dream state, with similar movements like feeling as though you are falling or floating. Their might be a distinct lighting change and one can feel an extreme tone to where they have traveled. Even other-beings and higher dimentional energies can pull one into an astral projection. Thei identity may be unkown but when mutually comfortable they usually reveal themselves, and often teach and show you things not found Most likely a spiritual guardian/guides such as a deity, angel, demon, animal, extra terrestrial, etc.
Not all experiences are lovely and sensational, unfortunately entities and realms can be macabre and really drain someones energy and personally balance =- once awoken. Astral projection takes precision and planning. You need to find techniques and rescources to help you on your path. Common techniques to a certain majority are: Monroe Technique, and the Mind Control Method by Joe Silva. If you are really intruiged, there are many novels on the science of it, and how to learn/master.
I hope this helped !