How do I write a letter to each and every spirit, thanking them for their service and giving them essentially license to depart without being disrespectful or rude to them in the process?
And then burning the letter is enough to seal the deal as a petition spell or pact?
Then write a thank you in the post topic Thanking Spirits?
Written as a notice to newbies, and just to get info for myself.
Thanks,…
I just say, “Thank you, [Name]” and then I go on with my life.
Or at least, that is the simplest license to depart. It works well too.
I always say ‘Thank you, you may leave in peace.’
A simple thank you is usually enough but I have done the letter method for the bigger workings, when the first successful working of a spirit I am interested in developing a relationship with later (where I will usually end it with something like “Depart with peace until we meet again”) or if I do not plan on working with them again in the future (usually this would involve not only thanking but pointing out things I learned in the experience that I will carry with me as I go on with life if it was a pleasant experience). It really tends on the mood and context, as building a good reputation with spirits has been beneficial for me within reason. I also do not write one for every pleasant experience with one spirit, as I do not want to cheapen the gesture.
As how to write the letter, treat it like a thank you card would be my best advice while ensure the call to depart is there if appropriate to the situation.
Burning the letters has seemed to be enough for me, but I would go with your gut on that one in the moment.
Thank you all 
“spirit x I now grant you license to depart, return to your home or abode in a way that none are harmed and may the peace of God ever remain between us I bless you in the name of tetragrammaton. So mote it be”
“Thanks homie.”
Probably works just as good as good as the any of the others
I should clarify that wouldn’t talk to someone such as Bael, Agares, or Paimon that way, but some spirits really do appreciate speaking more casual like that once you get to know them.
King Bael is surprisingly casual with me at times though, saying stuff like “no problem” after I thank him. His sense of humor, foregiveness, and more laid back demeanor makes me feeI comfortable talking to him about anything. He’s like a kind, loving father or grandfather to me, but I still always feel compelled to be more formal around kings and dukes, even if they personally don’t mind being addressed in a less formal manner.
Furfur is one who’s very up-to-date on modern language and culture, and will talk casually to you even if you don’t expect him to. In his male aspect, he reminds me of (and sounds like) McLovin from Superbad or 9S from Nier: Aotomata, and is a total ‘bro’ and sweetheart once you get to know him. To him I’ll usually say stuff like “thank you, my brother from another mother” or “thank you brother”. He does have a female aspect though, which is usually more serious, and when I’m addressing the ‘countess’ I’m more formal.
Marbas is more direct, and straight to the point, but with a dry, dark sense of humor almost like Dr. Gregory House, so with him it’s a bit different. He’s wise, intelligent, and laid back, but doesn’t really give much of a shit how you talk to him, address him, or thank him. They all have different personalities, and after a while you figure out how to talk to them. Marbas happens to be one who won’t hold it against you either way.
With Orobas, I always feel compelled to be more formal, since he’s very polite and sincere, thus I take his status as a Prince with utmost dignity and formality. I try not to joke around too much around him, since I haven’t (that I know of) had a one-on-one conversation with him on the etheric yet. I really do want to get to know him better though, since he seems to have a more casual side to those he’s been friends with for a long time.
My experiences are very very similar to yours @Tigris.