Something I have done is use the Pluck (or other VCO) playing an arpeggio into the Clouds reverb then use a different sequence to play sections of the reverb chord wash. Do a google and search for 'Trance Gates' and find something like this
And this was my take on it
Enjoy your spare HP, don't rush to fill every last space, this is not like filling sticker books. Resist the urge to 'complete' your rack, its never complete so just relax.