There are cheaper, and probably less effective options out there (including standard moving blankets), but I've actually had
very good results with these in my bands practice/recording space...
http://www.audimutesoundproofing.com...sal-space.aspx
I had them draped over some clothing racks to use as portable/easily movable gobos in the corners and in front of the drums... made quite a large difference.
For the floor, buy some cheap area rugs.
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c