A mistake I really hate to see in ad AdWords is when advertisers use really bad ads. They just write ads and you can tell right away by looking at them.
One of the biggest mistakes is using the company name in the title or using the company slogan. They simply don’t make good ads.
Another thing people do – they try to be too creative or funny or witty in their ads. This really doesn’t work that well with AdWords ads. When people are on Google searching for something, they know what they are looking for most of the time. They are pretty concise, and they want to see an ad that gives them exactly what they’re looking for.
A common technique that most advertisers use is using the keyword in the headline of the ad. Try to sprinkle the keyword throughout the rest of the ad too if that make sense for what you’re selling.
Don’t try to get too creative or too crazy with your ads. Make sure you use the keyword as much as possible. Highlight your unique selling proposition: What makes your company better than the next guy’s ad. And then, if possible, include a call to action. Tell the searcher exactly what you want them to do. Do you want them to call you? Do you want them to come learn more about your product? Do you want them to come shop now on your site? Tell them what you want them to do and there’s a good chance they will listen.