I use two main methods that I believe both get to varying levels of the astral or above. If one wants to explore maybe do some rituals or spells or talk with entities here or there the first method I think would be fine.
Though there are a couple submethods I’m aware of people use to get to different parts specifically, like negative pathworking that uses Sorts of sex actions or hurting or self destructive or hindering behavior/actions which could be dietary or physical related or not (eating a lot of sugar before bed, excessive drinking are examples).
Then there’s the submethod people do where they go into seclusion and give up much more than what they have need to in attempt to get results easier or actual, be it Total contact loss with people of certain sex or nature, certain foods, (like some monks will).
If one wants to go explore the regions said to be way vast compared to normal yet just as real, those places said to have the most Powerful powers and true magick, then I’d argue both or at least the latter method would be the Best (If you can find a place its taught or shown/given).
The first main method/way I learned to do is a waking induced lucid dream practice (WILD), it involves a main aspect of visualization and imagination based on feeling of movement/orientation.
Some people talk about how they (paraphrasing) visualize a spiral staircase and imagine walking up or down it and trying to feel that same feeling as if so, and after a point the actual clear detailed world some call fully lucid dream. I like to personally feel as if i’m walking down a hall or in a scenery/woods and imagine seeing stuff move as I am, and
One useful thing I think is understanding what actions or diets will alter ones position in that world if doing that (or even when one falls asleep normally). For example, eating a lot of sugar before dreaming lucid or not in my experience irritate the body to help gravitate one to more “low” or dark or intimidating regional parts. Witnessing or doing hurt seems to act somewhat as sugar before bed would too in my experience and belief.
Though common and easy I believe this method will only let one get to a point, still veiled at enough level. I think its great for doing certain spells or summoning or scenic travel, or other creative reasons. I’d debate if its effective enough or safe enough for Everybody to do their work in a bit is all. One Does have access to endless things we don’t here or in higher/finer regions, for Free, making it Very Useful for loads of spells or rituals or pathworkings people tend to use which Want or say they Need things not attainable. Though that’s not to say they’ll actually work more likely than not if they aren’t actually gonna deliver that thing anyway (i believe a lot of rituals starts as symbolic confusions and assumptions but that’s just my belief)
A way I came to conclusion is seeing much clearer and strong Safe and Successful results of intentions through certain meditation and evocation or focus from and within That area, compared with doing the same in lucid dreams or just this world without aid from a clear inner area. Example like being harder to get rid of or Actually compel spirits in either just the physical or just the lucid dream astral, so some they might just follow people back. Or one may not be able to get true info from said spirits, or just not be able to distinguish between truth fiction or twists.
I believe meditation to clear what obstructs ones direct ascent and clarity and maximal ability (through the third eye or whatever one wants to call it) is how one can get directly to the Unveiled higher astral where some say all the records of knowledge are, and into the Mental/Causal/Cosmic or higher.
In other words too, theres a violet/purple light meditation where one may come to see like swirling clouds ideally purple or violet or blue, I believe the way to go into unveiled/upper astral or further directly, is to still/relax oneself enough there to manage to look into and through the clouds and see what magnetic like bits create and hold or tint them.
Then from there doing what’s necessary to clear them from the clear area in front. Be it a special charged mantra that its nature is to clear that as I use, or whatever energy or connection else can do the same. If one gets to enough I imagine they could likely affect that same within everybody else, truly Test anything/one, or use it to Surely attain whatever desire easiest and most Immediately, eventually, be it specific planar/regional travel, special powers, control over such in certain regions, or whatever/etc.