Go dark. No, don't turn off the lights, but rather paint the room a dark, rich color like burgundy or navy blue. Since light doesn’t reflect off dark hues as much as it does light tones, content displayed on your TV or projected onto a screen will look that much better.
Hide A/V equipment. Put all your gear in an entertainment center, closet, or utility room and use an RF remote to control your peripherals.
Create stadium seating. Electronic House suggests building a riser that has two steps that are each six inches high, with the top step built with a platform at least six feet deep to accomodate chairs.
Image: Home Theater Design Magazine