Hi Ted
I am self taught but I know should modulate from one key to the other according to the wheel of fifths,etc etc. I suppose keys do traditionally move upwards. I am guessing that this moves up to a finale.

Personally, I do what I want. You can use as many lead in chords as you want, but to simplify it, I might do the following:

Eb to F: Eb,Ebdim,Gm7,C7,F
F to Eb: F,Fm7,Bb7,Eb

The most important thing is to have the Bb7 before the Eb, and the C7 before the F.

I hope this helps
Bernie