You likely already have some phrases and special terms in mind that you'd like to promote in your ad text. However, I would advise you to research what your competition is highlighting in their ad copy before you write your ads. If the specials and pricing you are considering are not as compelling as what's offered by your competitors, you might want to pick other areas of focus to make your ads stand apart.
Prepare a list of your most important keywords to research. Choose high-traffic keywords that show the highest impression volumes to start with.
Perform the following steps for researching competition on Google: