Or variations upon that sort of theme.

"Give full rein to your imagination with our coverings."

Etc, etc. etc...

"give free/full rein"

"imagination" "creativity"

http://www.bartleby.com/61/14/R0131400.html

NOUN: 1. A long narrow leather strap attached to each end of the bit of a bridle and used by a rider or driver to control a horse or other animal. Often used in the plural. 2. A means of restraint, check, or guidance. 3. A means or an instrument by which power is exercised. Often used in the plural: the reins of government.
VERB: Inflected forms: reined, rein·ing, reins
TRANSITIVE VERB: 1. To check or hold back by or as if by the use of reins. Often with in, back, or up. 2. To restrain or control.
INTRANSITIVE VERB: To control a horse, for example, with reins.
IDIOMS: draw in the reins To slow down or stop by or as if by pressure on the reins. give free (or full) rein to To release from restraints; allow to go unchecked: gave rein to her emotions. tight rein Close control: kept expenses on a tight rein.
ETYMOLOGY: Middle English, from Old French resne, reine, from Vulgar Latin *retina, from Latin retin re, to retain. See retain.