The procedure to create, revise and adopt is defined by the community, and hence here on this document.
Categories P&G by character and status
Official policies; called official to distinguish from draft / tentative adopted etc.
Guidelines; less stricter than policies, but still need to respect, and hence needs community approval
In trial; drafts once approved and in trial for months (normally from 1 to 3). After the trial, community decides to adopt it as official policy or guideline, re-draft it or just abandon it.
Draft - draft either reviewed or yet; followable only one's own responsibility
Procedure
Draft - anyone can propose a draft either new or revision of an existing policy. For revision, Wikiquote:WikiProject Policy Revision may be informative.
Even before reviewing, you may invite the community to join drafting.
During the review phase, the community should determine if the draft will be a policy or a guideline.
Freezing - Once the draft is set in stone, the version is frozen. If a draft has no opposition and not been significantly edited since one week before, it can be considered to be set in stone. If a major update of the draft looks a good option, the draft may be better to go back to the review phase. Only the draft frozen can be requested for the endorsement or the final vote for approval to the community.
Request for approval - A frozen draft can request for approval. The way to seek approval may be 1) endorsement 2) vote or 3) silence. The term should be one week at minimum. "In silence" means the community has been invited to review the frozen version of the draft for a good term (at least one week, preferably more) and no one explicitly opposes. The recommended way is approval by endorsement, a clear expression of support. If the majority supports, some parts of the draft can be altered even in this phase. It must be announced on Wikiquote:Village pump and may on Wikiquote:Community portal#Goings-on.
In trial see the above. Starting a trial needs community approval.
Abandoment - If a draft is not widely supported and explicitly opposed, the community may abandon this version by consensus.