There are lots of things you can do to fill the space in between chords. You can play other chords, arpeggios, and scales or parts of scales. Here is a little exercise you can do to get you used to filling in spaces. No particular song here, just a little somethin somethin:
Key Eb LH/RH
4/4 time count in [ ]
[1, 2] Eb / F-G-Bb-Eb
[3] / F
[an] / G
[4] / Bb
[an] / Eb
[1, 2] D / F-Bb-D
[3] G / B-Eb-F-Bb
[an] / Ab
[4] / G
[an] / F
[1] C / Bb-D-F
[2] / Eb
[an] / F
[3, 4] F / A-C-Eb-G
[1, 2] Bb / Ab-Db-F
[an] / C-F-Ab
[3] Eb / Bb-Eb-Gb
[4] / Eb (octave higher)
[an] / D
[1] Ab / G-C-Eb
[2] / Ab
[an] / G
[3] / F
[an] / Eb
[4] / D
[an] / C
[1, 2] G / D-F-Bb
[an] / Bb-D-F (octave higher)
[3, 4] G-Bb-Eb
[1, 2] Db / Ab-Db-F (octave lower)
[3, 4] Cb / Eb-A-Db-F
[1, 2] Bb / Ab-Bb-Eb-F
[3] Ab / D-F-Bb
[4] / Bb
[an] / C
[1] G / F-Bb-Db
[2] / Db
[an] / C
[3] / Bb
[an] / Ab
[4] / G
[an] / F
[1, 2] C / G-Bb-Db-E
[3] D / Ab-B-D-F
[4] E / Bb-Db-E-G
[1] F / Ab
[an] / C
[2] / F
[an] / Ab
[3] Eb / G
[an] / Bb
[4] / Eb
[an] / G
[1, 2] Db / Ab-B-Eb-F
[3, 4] F / B-Eb-F-Ab
[1, 2] Bb / Bb-Eb-G
[3] / Bb
[an] / Eb
[4] / F
[an] / G
[1, 2] Bb / Ab-Bb-Eb-F
[3, 4] / D (slide Eb to D, hold everthing else)
[a] / Eb
[1] / Eb
[2] Ab / G-C-Eb
[3] G / F-Bb-D
[4] F / Eb-Ab-C
[1, 2] Eb / Eb-F-G-Bb
[3, 4] Bb / Ab-Bb-C-Eb
(repeat)
That's all. If yall want me to break it up and show you where I used other chords, arpeggios, and scales to fill in the spaces, just let me know and I will, lthough maybe some of you can probably figure it out. I wish I could make a midi of it, but i don't have the stuff to do it right now.