Fallen London and Sunless Sea

[Recaiden]

There are only bad ways to get Favours, and it depends on the specific group. Mostly it's a matter of learning which Opportunity cards grant which favours. Each of the PoSI items from the sidestreets, for example, add a card to your deck with a favours option. Be sure to have the right Connected Pet for the faction you want.

EXCEPT! If you are Closest To: Bohemians or The Great Game, you can Count The Days without needing to use any normal opportunity cards, which lets you farm Bohemian/Great Game/Docks/Urchins Favors, 1/each for 42 actions and 2 Abundant-rarity cards. 5x Actions in Wolfstack, 5x in Forgotten Quarter, 5x University, 5x Shuttered Palace, draw the card, repeat.

Some nice people have made lists:
Society
Revolutionaries
Bohemians
Church favours can be farmed by repeating the Hound of Heaven process. Requires a ship and having finished the main Dangerous storyline.
The Great Game
Hell Favours can be farmed by spying for them in Polythreme. Requires a ship and either a 5-card lodging or a lot of patience.
Constables
Criminals can be farmed by bringing Skyglass knives into New Newgate (requires going to prison yourself, of course)
Urchins
Docks Favours can be farmed up on Mutton Island, or in Watchmaker's Hill with the Chandleress if the airs of London are right (5% chance, damages your Dangerous stat)
Rubberies I can't find a compilation for.
Tomb-colonists have no list I can find either, but you can farm their favours while Exiled to the tomb-colonies.

There are carousels and storylets behind FATE purchases for some of them.

[Iruka]

Thanks for the help! Now I wish I hadn't sold my soul and changed my Closest To.