Ok so I've gone though many threads here and elsewhere and saw that building a small booth with foam would result in a boxy sound as the foam would kill most of the highs and not the lows. I record in my bedroom and don't wan't foam/audio treatment all over the room so I'm thinking about 2 options...
Note: This will be used exclusively for rap.
1. Making 3 panels connected together probably about 4 feet wide each, 8ft tall. The panels would contain 4-6 inches of Roxul Rockwool and covered with a fabric. These panels would be placed behind the vocalist with an additional panel created to be placed on the wall behind the mic.
2. Make a small vocal booth; 5x5x8. Use the same amount of Rockwool to pad the four walls of the booth along with about 40% of foam placed around the interior of the booth.
Now I've recorded in my room before utilizing 3 things; 1. a blanket to my immediate left, some 1 inch foam to my right and some 1 inch foam on top with the mic in the middle of all that; so it's like I'm rapping into a makeshift corner, nothing behind me and this is the result I got after mixing/mastering it myself.