Start with decent traps OC 703 705 rockwool, mineral wool etc. Whatever you do, dont go gluing Auralex type foamstuffs all over the walls like a madman, like I did!
If you use their glue, you need to use a chainsaw with a dragster motor in it to remove them, and may make some new windows in your house!
Theres a few doodz here on GS that make nice containment products, checkem out!