[Here is a peek of one of the small ebooks that I am currently working on.]
The first rule to remember about your motto is that it is supposed to be personal to you. The motto represents a channel which the spiritual and magical energies that you are exposed to during initiations and your private magical work are directed through. This channel should represent your spiritual aspirations, and not those of another person.
The fact that it should represent your own spiritual aspirations, and not another person’s, means that being given a motto by someone else, whether a guru or Order superior, is undesirable. After all, who knows your personal spiritual aspirations best? Hopefully, it is you.
Likewise, recycling the motto of a previous member of the Order is unwise, for the mottos of previous members represent their spiritual aspirations, not yours. Furthermore, a recycled motto carries with it part of the karma of its original possessor. A common initiate that many people recycle mottos from is Aleister Crowley, the founder of Thelema. While it is true that Crowley was a great Adept, and perhaps even the higher Grade that he claimed to possess, his mottos come with a heavy price. Before even remotely considering recycling a previously used motto, one needs to consider if they are willing to help another initiate (living or deceased) work on their karma while ignoring one’s own karma and aspirations.