It's nice to work in large spaces, but sometimes those large spaces will cause echo in your audio. Too much echo can be distracting to the viewer. Adding furniture like couches, or even inviting more people into a room will help to absorb sound, but that's not always possible. So in this space I setup Audimute sound blankets on Light Stands to help absorb some sound, block deflection, break up the emptiness, and basically just add texture to an open space.
I have dozens of these blankets, and can setup as many as required. These are the same blankets I used to line the walls in a DIY vocal booth (video and example seen here). It's not a perfect solution, but it makes a huge difference and it's easy to stow away for transport. You can try this with heavy moving blankets, and although that should help, I don't think they will perform as well as the more expensive Audimutes.
AudiMute Sound Absorption Sheets
I know the Audimute stuff is expensive, and only sold in packs of (4) or (5) count, so if you still need to look for sound absorption type blankets, there are a few on eBay (that look like heavy moving blankets) found here.
Audio Sound Absorption Blanket
There's also a few more varieties found over at Amazon (click here)
Audio Sound Absorbing Blankets