I don't know about you, but I call impromptu vomiting harm.
Impromptu thoughts are mental wild-flowers.
. . . in general, the Anglo-Irish do not make good dancers; they are too spritely and conscious; they are incapable of one kind of trance or of being seemingly impersonal. And, for the formal, pure dance they lack the formality: about their stylishness (for they have stylishness) there is something impromptu, slightly disorderly.
The true touchstone of wit is the impromptu.
The best and most telling speech is not the actual impromptu one but the counterfeit of it.
The cream of enjoyment in this life is always impromptu. The chance walk; the unexpected visit; the unpremeditated journey; the unsought conversation or acquaintance.
He stepped back and threw his arms out. "I'm always crazy around you Rose. Here, I'm going to write an impromptu poem for you. " He tipped his head back and shouted to the sky: "Rose is in red But never in blue Sharp as a thorn Fights like one too.
I'm just preparing my impromptu remarks.
The very best impromptu speeches are the ones written well in advance.