The coffin opened too early.
You never know what we'll churn up in cleaning a stall
Formal letters may be an endangered species, say apart from legal actions, but you may still find a need for a snappy closing line for other written transactions.
Here are a few of note.
“Laters!” got misappropriated.
Reminders of a very special introduction I had while living in Upstate New York. We’re still in touch all these years later.

Letter writing may be a dead art, thanks to email, texting, and online job application forms, among the changing means of communication, but one of the challenges of on-paper correspondence had been in selecting an appropriate closing line, which went right above your signature. (Few youths today, I’m told, actually have signatures. Ahem.)
As one bit of advice noted, “sincerely” is for lawyers, better to be too warm than too distant.
Here are some alternatives, should the occasion arise.
Gee, now I’m wondering about “Truly.” Or even, “Actually.”

Violas.
More advice and observations from novelists and other writers.

When it comes to flowers, wild or cultivated, just consider …