Celebration doesn't require a party. Mostly it means catching something before it slides past unnoticed.
There's a specific moment at the kitchen sink after dinner — plates done, nothing urgent left, the day effectively handed in. It lasts about four seconds. If you catch it, that's the celebration, and it's enough.
A good routine that nobody notices tends not to survive. Not because it fails, but because it starves. The noticing is how it gets fed. Every day is the demanding part of this, and it's demanding precisely because the moments are so small — four seconds, at a sink, with nobody else in the room to confirm it happened.