Hi Ted.
Just from thinking - so don't hang me up - I would say:
You end your tune with F, then F7, Bb, then Bb7 (or Bb+) and then Eb.
If you go further: Eb7 - Ab.
This is one way of doing it, but there are lots of others using more advanced chords; but to get started
Good luck.

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Solomusikeren