An experiment worked; how to proceed?

A post here a while back suggested placing blankets or quilts on the floor around, between, in front of and behind the speakers. Today I did just that and am pleased with the results, particularly with orchestral music. The sound stage imaging and bass are improved, and the shrillness I sometimes experience with violins and woodwinds is gone.

Although I'm fortunate enough to have a more-or-less dedicated listening room, for practical and domestic tranquility reasons this obviously can't be a long-term solution. The room is about 12.5' x 15' with a thin oriental rug on the floor, gypboard walls, 6' of (curtained) glass door along one wall, bookshelves against the front and back walls, and a 9'-12' asymmetrically vaulted ceiling.

This is my first foray in "room treatment." I'd appreciate any suggestions or ideas on how to make these benefits permanent. I wouldn't mind using bass traps and the like but don't have a lot of free wall space to devote to these.