Direct your viewers to take certain action via your ad text. If your ad copy is directing the visitors to take certain action, then it is going to influence them to look for that action on the landing page. Here are some examples of common calls to action:
Separate benefits from features. Focus on what benefit you are going to provide to your customers. For example, instead of saying "Buy New Power Efficient Furnace," it will be better to say "Go Green and Reduce Your Energy Bill."
Use keywords in your ad headlines: If possible, use keywords in your headlines. If your ad is triggered by a keyword, then users are more likely to click on that ad if they see the same keyword in that ad. It increases the relevance of your ad which can improve your click-through rate.
Have relevant display URLs: It is important to have user-friendly display URLs. Your users may be hesitant to click on strange looking URLs which could be mistaken as spam. Use your company's home page for display URL.
Have emotional appeal whenever possible: Try to speak to your intended audience. For example, use ad text such as "Feel Confident with the Way You Look," instead of saying "Improve Your Looks."