When it comes time to write your copy for an ad, approach it like a salesperson. Stick to the facts, use motivators, and do not joke(unless you now your market with directly identify with the joke or if you are absolutely certain you can pull it off). Avoid making a big picture out of what is considered not a big deal. Inform, educate, and motivate and leave out information that can not be proven upon question. Keep it clean and cut to the chase.

To begin, break it down. Identity exactly why someone should by from you. Picture yourself as the consumer and ask yourself what would I like for this product or service to offer that would immediately convince me to make a purchase.
The solutions you come up with can only be as good as the questions, so ensure to come up with good ones. Be sure to read the "rules of advertising", "principles of advertising", and understand motivational factors.