I took Brenda's fic As Time Goes By, in which Tony creates a pre-op ritual for the Avengers of macking on Cap, Clint feels guilty, and Steve misses Bucky, and thought to myself "okay, so let's add Bucky."*
This gave me As Time Goes By (The Fundamental Things Apply Remix), in which Bucky, remembering himself, watches the Avengers, watches over the Avengers, and eventually refuses to let Steve get away with erasing that pre-op ritual.
It's not what I wanted to write at the start - that fic was going to be The Passing It On Remix, and in it Clint was going to talk Bucky though his own, similar guilt, with a bit of a postscript of Bucky getting into the pre-op kissing - but that fic just wouldn't come together in time.
The Fundamental Things Apply is a little more lighthearted, a little recovery details-light, and ends silly and fluffy as hell. Once I accepted this was not going to be a Serious Fic, I guess I kind of embraced that? And tbh, the mental image of Bucky V-J Day kissing Steve made me smile for days after I wrote it.
*(Funnily enough, that's the same thought process someone else had for a Remix Madness take on the same fic.)