| A couple things you might want to try out:
ii-V13-I, moving keys down in whole steps. Play the root in your left hand and a four note voicing in the right. The patterns can be done with the 3rd or the 7th as the bottom note played in the right hand. Add 9 and 5 extensions to major and minor keys, add 9 and 13 to dominant keys.
Example:
Dm7-G13-CM7, Cm7-F13-BbM7, Bbm7-Eb13-AbM7, etc
This will only hit half the keys, so also start on DbM7 (i.e. Ebm7-Ab13-DbM7, etc). You can start on any key of your choice and move down until you hit the same key.
You can also do this pattern with altered V chords. Try the following:
V13(b9), V13(#9), V13(#11), V13(#9, #11)
Try the same patterns, but move down in keys by half steps.
Example:
Dm7-G13-CM7, C#m7-F#13-BM7, Cm7-F13-BbM7, etc
These can all be adapted and used with minor chord changes as well.
Another neat thing to do is to harmonize the melody to jazz standards. Pick a piece out of the real book and:
Play the melody note as the highest note of the chord. Play the root as the lowest. The notes in between can be voicings of the chord you like the sound of.
Hope this helps. | 
