Selling things you don’t believe in

You will, inevitably, be required to sell something you don’t care about, or don’t know anything about. However, doing a half-ass job isn’t an option.
Situations for example: working retail or commission work, and job interviews.
I worked at a big department store for a while and saw some of the ugly pricing junk that happens in those places. Such as $50 cooking set that I’d seen returned 3 times because people got it home, looked at it, and realized it wasn’t even worth $10. But I sold it. I sold those RC cars that got discounted from $40 to $5 after xmas. I sold those stupid store credit cards, even though I knew they were skeevy and a trap to get customers in debt to the store. It felt gross, wrong, amoral, but I did it because that was my job. There’s only so far Principles will carry you when you have a house to pay for and cats to feed.
How to do it though?
Step 1: Be unceasingly positive. Find good things about your situation and remind yourself of them often. Keeping your own morale up is important. Find good things about the customers you talk to. Complement your customers, make them feel good about themselves.
Step 2: Find out what your customer wants. This requires asking questions and listening to the answer.
Step 3: Find good things to say about the product. If a product doesn’t do exactly what your customer is wanting, find something close and explain how that product will work. Add in any surprise alternate uses for the product.
Step 4: Be confident. Look like you know what you’re talking about by looking the customer in the eyes occasionally, smiling, and keeping your body language Open. Body language is very important and one of the hardest things to control. But to stay Open, make sure you don’t fold your arms, hunch your shoulders, bow your head, or anything that makes your chest concave and puts a barrier between you and the one you’re talking to. You’ll never eliminate quirks like nervous scratching or fidgeting, but if you keep your shoulders back and arms from blocking your chest, this will cover most conversations you need to have with a customer.
How this works for interviews:
Complementing the person interviewing you makes them see you as a warm, approachable person. Keeping open body language further enhances that idea. It makes you into a person and not just another Resume to throw in the trash. Coming up with alternate uses for the skills you have, even if they don’t seem like they apply directly to the job you are applying for makes your skill-set versatile. Besides, you wouldn’t be in the interview if they didn’t already think you might be able to fill the position. Focus on the good things you, as a product, can do to fill the customer’s needs. They have a problem, you are the solution; you just have to tell them how.