Here's how I remember it:
1. Go to your local used furinture store and find an old sofa, preferably green and with a couple of holes in it. All the better if you need a brick to hold up one end., Also, an old chair and a beaten-up coffee table. Make sure nothing matches!
2. Get a bunch of cinderblocks, three or four long planks of wood, and presto! Instant bookshelf!
3. The Hendrix and Dead blacklight posters have already been mentioned. Same with the milk crates.
4. Mount your Sansui stereo on top of the bookshelf.
5. IMPORTANT: Absolutely no computers, video games, or modern phones allowed. Only old rotary or touch-tone phones. Color TV is OK, black and white is preferable. No cable, just rabbit ear antenna. Playing cards are OK.
6. No CD's. Vinyl albums only. Some cassettes are permissible.
7. Garbage bags in the windows. Curtains are so bourgeois!
So there you go. When your friends come to visit you can say, "Welcome to the 60s!"