As someone who travels regularly, I'm always looking for creative ways to get better sound from my audio recordings. Hotel rooms tend to echo and you don't always have control over the environmental noises. I went looking for a solution that would offer a more controlled sound and ran across professional voice actor, Harlan Hogan's, Porta-Booth, which is built from some fairly common components. You don't have to travel to find this solution useful, it's also a great way to tighten up your sound when recording at home without needing a whole room dedicated to recording. Making a few slight modifications, I put together a video showing how I built my own.
Required Components for the Portable Voice Booth
Studio Foam The biggest variation between my portable sound studio and the one Harlan Hogan demonstrates on his site is the foam. He uses Auralex Studiofoam 2" Pyramid foam, which is only available via special order from places like Guitar Center in $400 increments (or $200 via Amazon) - I know, I checked. If you want foam more like the original Portabooth, you might try the Sonic Homework pyramid foam. I opted for a sheet of 2x24x48 Auralex Wedge foam, which runs about $25 per sheet. It got the desired result and I don't end up with a box of leftover foam. The sheet is big enough to make 2, which is also the minimum number of cubes you can buy, so get a friend in on this project and save money. Any local music supply store should have similar foam.
Whitmor Cube The Witmor 14x14 collapsible cube ships in quantities of 2 for about $19.99 at Target.com, Wal-mart.com and Amazon (by way of Target). You can't get them in stores for some reason, so you'll have to order online.
Bread Knife You need a bread knife for cutting the foam - trust me it works better than anything else. A cheap Chefmate knife or any of the $4 or under variety, like the World Kitchen/Ekco 7" Bread Knife from Amazon are great solutions for this. Don't use your wife's bread knife unless you plan on buying her a new one.
Additional Tools The only additional tools you will need is a tape measure to make sure you cut the foam in the right place and a Sharpie to mark the foam to make the cut.
Assuming you already have a Sharpie and tape measure, you're looking at total cost of approximately $42 plus any tax and shipping for materials to make 2 of these cubes.
Space Saving Bags For Storage
I bought the Large Space Bags 3 pack from Target for my packing solution. You can get both the Space Bags and the Whitmor cubes through Amazon's affiliation with Target and spend less on shipping for the overall package (you can likely get a bread knife this way as well).