Simple rules to follow
1. Listen
2. It's their hard earned money. They will spend it they way they feel is best for them.
3. Listen
4. Ask as many questions as you can to insure you know EXACTLY what they are looking for. Or at least have a good understanding of what they want. And answer all of their questions.
5. Do not find yourself in a cookie cutter system mentality. Although you will have limited products to offer, don't fall into 1 or 2 receivers, or sets of speakers for everyone.
6. Always consider the WAF, Wife Acceptance Factor, it might be there home too.
7. Listen
8. Never, and I mean NEVER judge a person by their clothes!!!!!!! They may only have a few bucks now, but they may have more someday. Or, they could be Marshall Faulk who came into the A/V store I used to buy from, looking like he was homeless.
9. Never make things up, or act like you know what you are talking about if you don't. Be honest and let them know you don't know, but find someone right away who does.
10. Listen
Congrats on the job and good luck.