Haven't read through the whole thread (sorry!)
- Have a computer w/ internet so you can look up any information any time you need to
- Have some kind of music (not annoying) or sports TV station playing (not too loud)
- Be nice to customers, even if they don't look like collectors! I was pretty upset to visit an LCS here only to have the owner treat me like I was dumb as a brick, I think because I am a female
- Have some kind of social stuff going on (eg. the trade nights as mentioned)
- Don't have too much empty space but if you have tonnes of boxes of unsorted cards you should have a bench/chair/couch so people can sit down and look through your stuff
- Invite me to your opening!