Whenever you're writing a copy, always remember that it's not about you. Always remember to focus on your prospects, as they are the people you are promoting to. You could be the best in your industry and be many other things, but what your potential customers care about is your product and how it's going to solve their problem. How your product will help them is all they want to know. You won't be impressing people by telling them about your personal success story, you'll be turning them off. Your audience will tire quickly of hearing about "I" so make sure you tell them more about "you." Remember, readers who get bored hearing about you and your achievements can easily look up one of your competitors. Tell them as soon as possible what your offer will do for them. Throughout your copy, your focus should be on your customer. Another important tip that you need to remember is to keep all your focus on the benefits of your product, not the features. While you may have a product with an unmatched set of features, you will lose your readers' interest unless they can see what this will do for them. Your prospects don't really care about the way your product works, they want to know what problem it will solve for them. Just make sure that you list a benefit every time you mention a feature. Besides that, when your prospect talks about your product to his friends and family (word of mouth) he/she won't talk about the features but will only talk about how beneficial the product is. Even though your features make your product original, what people really care about are the advantages. You can create a list of benefits using bullet points.
There are different opinions on whether you should write long copy or short copy for the best results. The decision for either a long or short copy is up to you but studies have shown that a long copy gets better results. Longer copy allows readers to learn more about the product and absorb more information before buying. You can offer a shorter version of your copy for those people who don't want to read a really long sales page. To be a good copywriter you have to learn several different skills. It takes some time and effort to master all of these. This is why it's important to practice copywriting on a regular basis, so that you sharpen your skill along with profiting from the sales.