I) You can try a progression with a Turnaround.
When including the chord built on the sixth degree of the scale, it usualy is an Alt chod (VI7alt). And it is played after the I7.
C7.....F7....G7.....C7....A7alt....Dm7....G7
I7.....IV7....V7.....I7....VI7alt....iim7....V7
....................................Turnaround.
And that Theory applies for other instruments.

II) You can add extensions to the Dominant 7 chord, and even...alterationes.