When one incorporates Ceremonial magic into their practice they are in essence, engaging in the art of connecting with spirits. I personally believe that there is a misconception of such a practice in today's society. There is the belief that such a pursuit is endorsed primarily by those who engage in Black Magic. As an old school witch, I frequently engage denizens from the spirit world. I do this as a useful mode of understanding and enlightment without the connotation of evil that has been embellished upon by Abrahamic religions and Hollywood studios. I personally don't differentiate between White and Black magic.
Allow me to explain this viewpoint. I see spirits, demons, diva's and so forth as entities not of this material world. As such I personally believe that they don't fit into the moralistic views that humans strive to lable them with. Such labels generally derive from man-made religions and are used to validate the precepts of such religions. I personally see religion as an anathema to the freedom of the mind and soul. And hence I see other-worldly entities as beings that have their own sense of awareness of being/reality that may or may not coincide with human concepts. Much like a wild animal has a different level of comprehension and awareness then a human. This is not to say that humans will not incorporate such entities in an effort to arrive at results which their fellow humans may view as evil or dark outcomes. But again, such results are based upon moral interpretations as they currently apply to society.
On the other side of the coin, if one accepts the premise that these beings are of their own level of awareness, then there is also the possibility that such beings/spirits will engage in activities that are detrimental to the paractitioner/summoner of these beings. If I may use an anology, it is like being in the shoes of a lion trainer, you prepare the best that you can and then take your chances. As a further disclaimer of the moralistic aspects of summoming spirits, if one were to take a close look at ancient texts involving Ceremonial magic, one would see constant reminders and exhortations to meditate intensely on the undertaking at hand, and to make one's desired goal known to the God that is utilized in such a process. Adonai is the Hebrew name used in place of "YHWH" as a name for their concept of God and is the God that is frequently invoked during Ceremonial magic rites.
There are four Grimoires I personally reference when seeking guidance on the preparation of summoning spirits (or demons or what have you). They are the Secretum secretorum (Secret of secrets) not to be confused with "Kitab al-asrar" (Book of Secrets) which was written by Muhammad ibn Zakariya al-Razi. The "Grimorium Verum", or the "Most Approved Keys of Solomon" which was published by Alibeck the Egyptian in 1517 C.E. The "Grand Grimoire" and "The Constitution of Pope Honorius the Great."
I use these references because I personally believe that preparation is of the utmost importance when connecting with other-worldly beings for whatever reason. I tend to substitute the Christian/Hebrew implications with my own insertions based upon my own interpretation of Deity, but I do follow the descriptions of talismans, symbols and such to the letter. The reason for this is that the summoning of spirits began centuries ago, long before my presence on this planet and such experience from learned folks is invaluable when engaging such a discipline. For instance the Grimorium Verum contains 45 Talismans to be used in conjunction with the art of working with other-worldly beings. Within the grimoires are tables which contain certain periods of the day and night which are ruled by certain planets. These tables are invaluable when engaging other-worldly entities. For exmple, the "Key of Solomon the King", states that the hours of Saturn, Mars and Venus are good for communion with spirits, the hour of the first named planet for invoking souls in Hell/Hades; and that of the second for those who have been slain in battle. Another example from the same grimoire states that the best time to converse with spirits should be made in the day and hour of Mercury: that is the 1st or 8th, or the 15th or 22nd day.
In addition to these tables, there is information as to the proper method of purifying and consecrating, the type of tools to be used, how to properly cast a protective circle and many other topics which should be adhere to in detail. It cannot be stressed enough that such preparations are imperative in order to arrive at a desired goal when conjuring other-worldly beings. Short cuts can lead to deadly results for the practitioner. In addition to the grimoires previously mentioned, there are of course other grimoires of equal importance. The practitioner must choose that which works in favor of the individual.
For instance, if you follow the path of Voo doo, then you are probably familiar with "Le Veritable Dragon Rouge" ("The True Red Dragon") which was discovered in the tomb of Solomon in 1750 C.E. Another example is the Munich Manual of Demonic Magic which was written in the 15th. century. Other examples are The Book of the Sacred Magic of Abramelin the Mage also written in the 15th century, the 6th and 7th Books of Moses, published in 1849 C.E. The Heptameron (Seven Days) of Peter de Abano (1496 C.E). The Libri Tres de Occulta Philosophia (Three Books of Occult Philosophy) by Heinrich Cornelius Agrippa which was written 1531 C.E. and so forth.
In closing, no matter what source material you use to summon spirits, do not undertake such an endeavour as a matter of curiosity or approach such a discipline in a cavalier manner. There are no secons chances and short cuts and/or mistakes carry a heavy penalty for you the practitioner...