Levels of magic are sometimes called levels of consciousness. They are important because they tell you a few key magic concepts and which magical current goes where.
Traditionally when you look a theosophical or Neoplatonic philosophy they became rather unnecessarily complicated so what follows below is a simplification.
God’s mind is split in three divisions there is the conscious, unconscious and matter. The matter level is what we see with our senses while the divine unconscious is depicted in concepts like the underworld. The conscious mind is the animating force which unites creation. It brings new ideas into being. This conscious mind is divided into four.
The sub-lunar level
The Sub-lunar level encompasses matter and the astral and the lowest level of the underworld. It is the realm the Goetic magician who uses magic drawn from nature, the elementals, the dead, terrestrial daemons. They also take power from the symbolism of the moon gods such as Hekate, Diana, or the Archangel Gabriel. These channel celestial and divine power into the material and astral realm.
Note the word Goetia does not just mean demonic magic. It is the most common form of magic as its function is to effect the material plane, the thoughts and minds of people, and the daemons of the Gods and work with the dead. Although many magicians claim to aspire to celestial, or divine forms of magic, the bulk of their work is Goetia.
It needs little in the way of purification. Sub-lunar magic is powered by elemental energy from below, or from “the moon.” Its rituals often feature calls to nature or the elements to bring about their goals. Its magic depends on some form of sacrifice to transmute one type of energy to another. It is enhanced by repetition and chanting. Its rituals are best conducted at night according to the waxing and waning of the moon. The magical use of pathworking or astral takes place at the highest aspect of the sub-lunar level where it can influence the celestial or divine level closer to their source.
The Celestial level
The Celestial level is the realm of the divine Gods or archangels. They have their foot on the lunar levels but are divided into seven broad categories as expressed by the planetary forces. The Celestial forces manifest in the upper parts of the sub-lunar level as the different masks of God. At this level they are closer to their energic and functional nature. It is their job to bring the divine ideas from above so that they can be properly experienced by Hekate in the sub-lunar realm. Magic at this level is the work of the Theurgist or god worker.
To achieve the levels of consciousness necessary the theurgist must separate their soul from matter and purify it so that it may respond to the energy of at least one of the seven energies found on this level. Rituals seeking to attain this level are called ascensions and through periods of attunment to the divine energy the theurgist starts to embody that divine energy.
Such rites might start on the sub-lunar level which provides a bedrock for an astral ascension. Symbolically this level is under the control of the Sun, although others see it under the rule of Jupiter or its equivalents such as YHVH. Note the purity required to attain this level is not the sort of purity demanded by religious abstinence, fasting or other taboos. These are symbolic of the true purity which is the adoption of a mindset which operates at the Celestial level and not at the material. The work of the Theurgist is to provide a conduit for these powers into the astral and then use them to ascend still higher into the Super-celestial level.
This realm is the closest that a human mind can go to entering the mind of the one thing. It is not something that can be managed all the time, but it can be glimpsed. This is a world without form from which the seeds of reality are formed. Attaining it requires another change of mindset from microcosmic to macrocosmic and it is the realm of the mystic. Stepping into this world requires the aid of the Celestial forces and further purity.
There is no ritual that will help, other than working at the Celestial level and having them aid you. As in the celestial level you should become more like the one mind to truly understand it. This level is symbolically controlled by the stars which in ancient times meant the fixed stars. Realistically they are far above that and is the place where the ideas come from. Stepping into this divine mind is what is meant by crossing the abyss.
Using this pattern, it is possible to work out what sort of things you should do to succeed in magic. You should work at the level of the magical target. If you are going to work at a goetic level do not pretend to work at a celestial level. You need the lunar powers and the powers of nature to make the ritual work. Use the daemons of the gods and follow the rules of the sub-lunar realm, focus on sacrifices and offerings. When you want to step out of that you get into the more abstract celestial levels then use the rituals to peak within a pathworking to the energy you want to experience. Then after a few decades of working with them you might be ready to have them lift you to other levels.