Put yourself in the customer's shoes. Tell the customer what you will do for him. Don't tell him how wonderful you are. Tell him how you will improve his life. If you can't improve your customer's life then quit now and find a different product or service to sell.
Sell benefits not features. The statement "Improves engine life by 14 percent" sells more lubricating oil than "Contains patented additives." Make sure you can backup your claims.
Stay positive. Advertise toothpaste by saying "Makes your smile whiter and sexier" instead of "Prevents tooth decay."
If your product has a unique and valuable benefit to the customer then push that benefit. That benefit is called a "unique selling proposition" and that USP must be the thrust of your marketing. If you are lucky enough to have a USP and you market properly then you will become rich.
Figure out who needs or wants your product and can afford it. This is called the "target market." Try to think like they do. Then ask yourself why they should buy from you rather than somebody else. If you can think of reasons that your target market thinks are important then tell prospective customers about them. If you can't think of any reasons then you need to improve your service or product to create a reason.
Your marketing efforts must be directed at your target market. Offer delivery to the places where your target market lives and works. Choose purchase terms, hours, locations, and policies that are convenient for them, not for you. Place advertisements where your target market will see them. Speak the same language. Your approach will be totally different if your target market is factory workers instead of university professors.
Identify your competitors. Why is your product better than theirs? How are they doing business now? Can you learn anything from them?
Listen to your customers and especially to the no-sales. If you are lucky then you will have loudmouthed customers who complain about every defect, tell you exactly how your competitors are better than you, and demand that you provide the new items and services that they need. If you are very lucky then people will tell you why they decided not to buy from you. Otherwise you will have to dig. Ask friends, acquaintances, and your family what you are doing right and what you are doing wrong. Most customers hate to give negative feedback. They will just go somewhere else next time. Ask customers "What could be better?" instead of "Was everything all right?" Also ask "What other problems do you have that I could help you with?" Market research firms will do this digging for you if you are willing to pay them lots of money.
"The best way to increase the sale of a product is to improve the product." Advertising expert David Ogilvy, who won the Parlin Award for Marketing, wrote that in 1983.