The first and probably easiest method for choosing a name is by simply looking one up. A person can choose a name based on qualities they possess and want to be rid of, like the woman with the prickly personality who calls herself "Porcupine." Then, we'll all know to stay clear of her when she's starting to take aim with her quills. We can also choose names than can imbue the practitioner with certain qualities and personality traits that can help us avoid illness, bring luck, or remind us of where we're going or of where we've been. There are many god and goddess names to choose from, if one wants to be more connected to a particular deity.
Another way many people find their name is to choose from magical or ordinary items in nature, animals, runes, and heavenly bodies. Some even use seasonal names or times of day—Winter, Dawn, or Autumn, for example. Summer Twilight would combine the two. People sometimes choose the name of their power animal, and then use a native or ancestral language, such as Tala, a Native American word for "wolf." You can also choose a magical name from characters in books or movies. In fact, you probably already know at least one Gandalf or Galadriel, and will soon probably know folks named Dumbledore or Draco.
A method in the book Attainment Through Magic, by William G. Gray, utilizes the three-pillar scheme of inquiry of the Qabalah: First, you identify your dominant intellectual characteristic and write it down. Second, you identify where you feel you are at emotionally, and this down also. Last, you determine what you think you ought to become as an immortal entity. This, in Pagan terms, can also be interpreted as your definition of Divinity, or the Godhead. At this point, you should have three words or phrases in front of you that can then be translated into another language, or are runic or another symbology. Then, you string the words together, trimming the newly formed word until it sounds right to your ear, keeping only select parts of each word to remind you of their meaning. For your "outer" or "public" name, you choose the part that stands out to you, or you can create an acronym—a name from the initials the individual parts form.
An example would be the man who is a computer-systems analyst who is very good with numbers. He chooses the word four, since not only is it a number, but also it is the number of the four directions. He is learning to be more outspoken emotionally, and he has had renewed success with his relationships because of this. He chooses the god name Neptune out of gratitude for his help in this area of his life, and also because he aspires to be more like him. He feels that the gods are pure, unconditional love and happiness, so he chooses the word joy.
From the Czech language of his ancestors, he changes four to ctyri (pronounced shti-dee). He keeps the original spelling of Neptune, and from the runes he chooses wunjo, which means "joy" and "light." The long word name becomes ctyrineptunewunjo. After some careful manicuring and the addition of a y to make it sound finished, he decides on ctyepwunjoy for his long name. He keeps the larger part of the name secret, mostly to keep his friends from tripping over their tangled tongues, loving the sound when he whispers it to his gods, since the c-t-y is pronounced "sht,"so his name when spoken sounds like "schtep one (is) joy." His "outer name" is then, simply, Joy. An unusual, perhaps even "fantastical" name for a man, but luckily he is a Pagan, so the most common reaction to his name is a smile.
Another example would be a woman who sees herself intellectually as being pretty smart. Emotionally, she aspires to be healthier and hopes to someday be a counselor. Her vision of spiritual aspiration is a rainbow of color and music. She chooses the word east for her intellectual aspect, since the east is of the mind; and for her emotional healing energy, she chooses the word cobalt, for the deep blue of emotional energy. For the rainbow, she chooses the goddess Iris. The long name she comes up with after some trimming is Easbalier, and for her outer name, she uses Bali, right out of the middle, since it sounds airy and somewhat exotic to her.
Excerpted from Dedicant, by Thuri Calafia