Copywriting can be a funny thing because it's very easy to take it for granted. It doesn't come across as something that hard. However, very many people have discovered the truth about copywriting when they sit down to write it. It can be hard to write copy that will get the job done if you don't have the knowledge to write good copy. That's the simple reason why so many businesses hire professional copywriters. Even if you choose to do this, you should make sure that you know the basics of copywriting so that you understand what your copywriter is doing.
For a long time, people used capital letters to emphasize the points that they wanted to make. Not any more because now the understanding is that you're upset and shouting, or yelling, or screaming. In the world of copywriting, to make an emphasis you will underline, bold, or use italics. You can do that plus use a font color other than black, such as red for example. Also... USING ALL CAPITAL LETTERS IS HARDER TO READ. Right? Font format changes can add real power to your copy, so don't ignore it or be intimidated about trying it.
You won't find any specific rules that your copy must be this/that length. There's a misconception about copy that the longer it is, the better it will convert. Not good - that's not the correct reason to write more. Always make the length it needs to be to get your job done - no more, no less. You'll destroy your letter if you add filler just to look better. If you need more words to correctly and accurately get it done, use them. After proof-reading your copy, frequently you'll find words/copy that doesn't really need to be in there, so you cut it out. Remember: No special word count involved in copywriting.
Stay away from excessive formality in your copywriting. The way to make that important emotional connection is talk to them like you're talking while having coffee. People want to buy from sellers who make them feel comfortable. You'll see lots more sales if your readers have the feeling their talking to a long lost friend. Formal words and stiff styles does not accomplish that goal. If your market expects formal tones, then it's smart to talk to them with it. Becoming a good copywriter often takes years of work. It only looks simple because good copywriters know how to make it seem that way. Even if you don't aspire to be a professional, you need some copywriting skills as an internet marketer. Copywriting comes into play in so many aspects of internet marketing that learning the basics can help you in many ways. Copywriting is, after all, what causes people to buy your products. Copywriting is absolutely essential, as people have to be sold on your products before they will part with their money to buy them.