You need to really analyse your niche and be clear about the language you use so that you don't get people clicking by mistake. And brevity is important - being able to get your point across in as few words as possible. Example We rent out portable cabins/sleepouts for long term use. In our city we can say "cabins" and people know what we mean. 3 hours down the road you get to a tourist hotspot and "cabins" are things tourists hire for a week. Think about who your audience is, and which ones you want clicking through.
For free ads: you can use coupons. For quality ads: - You need to analysis your business and product. - You need to select your market area which audience you want to target. - Select only relevant keywords - Create relevant landing pages - Create account and campaign - Use relevant keywords in each ad-group - Use negative keywords to block unwanted impressions - Focus on quality to increase CTR