To what extent are they effective? Can I ask for multiple things in one petition to a spirit(ofc offering things in return)?
Also, when you burn them, do they have to be completely burnt? Or instead of burning can I just bury it in the ground. Thanks
There really are no limits to petitions. You can ask for anything.
When you burn a petition, the goal is to send your request to the spiritual realm through the gateway of fire so yes, it should be completely consumed and the ashes given to the wind.
Yes, you can bury a petition instead of burning it. As the paper rots in the ground, the underworld spirits will take up your requests. This is a classic way of cursing your enemies.
If I bury the petition, will what I ask for take slower to fruition?
Generally, yes because it takes time for the paper to rot in the ground and be transferred to the spirit realm. If you want a quicker method but can’t burn it, I recommend just ripping it up and throwing it into either a moving body of water or cast it to the winds.
So I should do the ritual outdoors then
Not necessarily. You can rip up a petition and throw it out the window or even flush it down the toilet if you have no other option.
What do you think would be the best way to get the spirits attention of the petition? Like should I write the petition first things first in the ritual, then meditate? Or the other way around
You have to think about what you want to write about it, don’t you? Do both at the same time, and spend some time visualising the successful outcome before burning it.
Do NOT dwell on what you are lacking, that will manifest more lack - meditate that this is already happening and it is already done.
There are so many ways to do.
If you are very familiar to the elemental ways : you can burry a petition linked to an underworld spirit.
Throw in a river a petition that deals with water deities.
Burn down any petition that has solar correspondances.
Tear apart in the winds any petition link to a sky spirit.
In 2024 though we tend to be more careful with it cause we are more eco aware than people from the past. So we either choose eco friendly material or use more energetic ways (like imbueing an offering with our intent)
very effective, pretty much limitless. you dont HAVE to burn it, other means will be fine but may be slower. you can bury it, rip it, soak it in water, flush it, shred it, etc.
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That depends on how strong your intent and will is rather than on methods and wording ofcourse. But always better to :
Meditate/ visualiize your desire and then write your peition and then meditate again on desire before firing it off.
Also simple petitions are underestimated by some but wait until you see how they will shake your reality and u unable to comprehend 
I agree.
A petition combine the power of writting, eventually rhyme if you choose to. It helps to visualise, hold the energy and then realise it when destroyed.