I'm making this thread mostly to explain how I got the achievements, feel free to add your own guides
#Achievement Guides (SPOILERS INCLUDED)
sudden coral
For starters, I'll personally only do the ones I would consider "out of your way," as personally, most of the others I got by just playing the game without even going out of my way to get them.
Order, Sate, Cure, and Peace:
the tried and true method used to be just bonk them with golden fleece. As of today (8/24/2022), however, the Golden Fleece now caps out at 200%. Now I would suggest Glass Cannon combined with the Hounds curse or any other curse that hits multiple times. The more cards you get that affect the damage and/or the amount of curses you can cast the better.
Full deck:
Most of the cards are unlocked by default.
Another good chunk of them can be purchased from various vendors such as any of the NPC areas besides Lonely Shack, Forneus in a crusade (look for a Shop floor with the Cat icon below it), and Ratoo in a crusade (look for a Heart Floor, he does not sell you the card in his challenge floor).
4 can be won by beating each of the 4 Knucklebones contestants for the first time.
1 is obtained from getting the Law & Order II doctrine and either marrying a follower or sparing the loser of a ritual fight.
1 is obtained by buying 5 followers from Helob. I'm not sure if purchases from Helob outside of a crusade counts but I do know that the card can only be obtained at his crusade shop (look for a Shop floor with a follower icon)
And finally, 1 is given by the fisherman during his quest.
Transmute:
Holy Talismans are needed to unlock Fleeces. There are a total of 20 Holy Talisman pieces scattered throughout the 5 NPC areas.
4 pieces can be obtained for each of the 4 fish the Fisherman asks for
Sozo gives you a piece for each stage of his questline
Plimbo gives you a piece for each Witness Eye you bring him. There are 4 Witnesses, 1 for every level you've killed the Bishop for.
Midas give you 4 pieces in exchange for sacrificing 4 followers at his throne
The Fox/Wolf/Ravenous Night gives you a piece every time you finish a step in his questline. To do so, go to 4 locations at night; the pier of Pilgrim's Passage, the pier of Smuggler's Sanctuary to the right of Plimbo, the left side of the starting area of Spore Grotto, and the top right corner of Midas's Cave. These can be visited in any order but the order of items he asks for doesn't change. In order he will ask for a large fish, one of your followers, either chunk of your flesh (which takes away a half of one of your red hearts permanently) or two of your followers, and then finally... well I'll let you figure the last one out.