Read the poem "Words Written Near a Candle" by Tess Gallagher.
"..it is all right to make a distance
of a nearness, to say 'Boat, I have left you
I am with you.'"
With these words in mind, write a goodbye.
Maybe it's goodbye to an ex-lover, or someone who's no longer alive. To a best friend you've grown apart from. To a past self. To a home, literally, figuratively. To your beloved copy of "Watership Down", drowned in the bathtub (never happened). To yesterday. To 2017.
I often come up with these prompts with poetry in mind, but I like to keep them loose enough that they can be adapted for fiction or other forms of prose. You could, of course, write a goodbye story. You could even write it in the second person (gasp!).
Go forth. Sink into some heart feelings. I know I will.