1) Think about your Readers
When writing ad copy be sure that average reader can easily understand and relate to it. Put yourself in their place. Would you understand? Would you say, "That's me"? One way to help you write for your readers, is to write just as if you were saying it to their face. Address reader as "you" in your copy. Just like a one on one conversation. Sometime take a closer look at some of advertising around you. How many times do you see them using "you"?
Make your copy interesting to read, almost story-like, all time generating enthusiasm for your product or service. Find ways to place facts in your copy without sounding like an Army Service Manual. The trick is to convey hard dry facts and numbers, while making them interesting to read.
Don't talk about yourself. Readers don't care what you like, what you did or what you think. They want to know if they will like it and how it will benefit them.
2) Organize your Copy
When you write your copy you should always know what your primary message or selling point is as well as all secondary selling points. You might want to use your primary message as part of your headline and then dedicate a few lines or paragraph to expand on it. Then fit in your secondary selling points in lines or paragraphs after that. Whether they are a few lines or a paragraph would depend on size of your copy. How much space you can set aside for your selling points? Before you start writing your copy write down all your selling points. Sort them in order of importance. When writing your copy, move smoothly from point to point, one leading into next.
3) Short is Better
Everyone knows that short sentences are easier to read and comprehend than long sentences. One thing that all writers have in common is that they are taught to write short and to-the-point sentences. Read back through your copy. If you find a sentence that has more then 12 words, find a way to break it down. Break all long sentences into 2 sentences. If necessary, break them down again. You can also use hyphens to help separate long sentences. This is not to say that all your sentences should be same length. Copy can become boring when sentences are all same length. Vary their length. Just keep them under 12 words. Remember you are writing copy, not fiction. Sentence fragments, as long as they sound good to readers ear, are completely acceptable in copywriting.
4) Don't be a Dictionary
Use simple and easy words. That's what a reader understands. Consider mindset that you are communicating with. This reader is not trying to dissect and devour your copy. This is someone, who for one reason or another has been distracted from their primary goal to read what you have to say. It's only a short pause they're taking to quickly read your words. If you use complex words, you will either annoy or completely lose your reader. Keep It Simple Stupid! Ad Copy is Communication. Don't think that you are impressing them with words they probably couldn't spell and would never use themselves. Make it easy for reader to understand and keep up with copy.
5) Keep Clear of Tech-Terms with Wide Audiences
If your copy is to be read by a wide audience, don't wrongfully assume that they will know what you know. If you feel that these facts must be used, find a way to convey these terms in best way that they can be understood. Don't use a technical term unless it is best choice. Sometimes you have no other route than to use technical terms. Lets use "software" as an example. What other way can you put it? It's software. But then again you wouldn't want to say "C++ Software" just Software. The average reader has no idea that C++ is a programming language and could care even less.