I'm doing a business management program for engineers right now. Here are some tips that I've gotten out of it:
- As a salesperson, it is your job to match customers with the right product. Don't sell them something they don't need or want (because they will have buyer's remorse later and they might not shop with you anymore), show them products that you think will actually satisfy a need for their life.
- Value keeping long-term customers because they are the most profitable and loyal. I don't know what kind of sales job you're in, but don't ever try to scam your customers by obnoxiously trying to sell stuff they don't need or lying to them. They will find out, it will catch up to your company, and you will not only lose the customer, but they will spread negative information to other people. You want the customer to be satisfied with their purchase so they feel comfortable enough to come back and tell other people to come as well.
- It's your job to KNOW ABOUT YOUR PRODUCTS. If the customer knows more about what you're selling than you do, you're not doing your job well. Also know about your competitor's products because customers often ask "what's the difference" or "why is this more expensive/cheaper" and you have to know how to answer those questions. A good salesperson, as I said, matches the right products to the right customer.
- Pay close attention to the customers. What products are they looking at? Did they come with a family? How old do they look and what's their gender? You can often tailor your suggestions to parameters like these to more easily find attractive products for the customer.
Hope that helps. Stick by those and I think it might make your job much more successful.
Combine that with the other stuff in this thread and I think it'll help.