I have become very slow and stupid, and will no doubt soon become overwhelmed by all the great fic out there to be waded through, but here are three little ones I found on my ownses:
Same Old Song and Dance
(The Good Place)
https://archiveofourown.org/works/16983300 Michael and Eleanor. Has a lightness of touch that feels just right to me.
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The Marvels of Whitby
(Medieval Manuscript Illustrations)
https://archiveofourown.org/works/16927806 Epistolary tale of two monks arguing about bees and battle snails - a tiny gem, just as finely-detailed and colourful as its subject matter.
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Piracy Is Our Only Option
(Sense and Sensibility - 1995 film adaptation)
https://archiveofourown.org/works/17144882 More epistolary goodness - Margaret runs away to sea and sends letters home. Delightful and the style is perfect.