Improve your Ad Relevance:

1) Create focused and tightly themed Ad Groups: It’s a good practice to create an individual ad group for each product or service you want to advertise. A good guideline is to have between 5-20 focused keywords, per ad group.

Ex: If the campaign is about insurance, Ad Group is car insurance, then keywords in this Ad group should be related to car insurance only.

2) Try to use your main keyword in your Ad copy headlines, description and in Display URL

3) Ad copy must match the landing page’s content.

4) Use negative keywords to hide your ads on those search queries. 

Improve Landing page experience

Basically, you have 10 second to attract and engage your visitor on your landing page, the more than spend time and more likely to convert into leads. 

• Landing page headline: Your landing page headline is critically important, it is the first thing that the user engages with after landing on your page. It helps the visitors in knowing what your landing page is all about. It should explain what is it about and what benefits they get in simple less than 6 words headlines and less than 20 words in a short summary.
• Focus on a Single Goal: Create pacific landing pages for different campaigns & AdGroups
• Focus every element of your landing page on the benefit to the user, including the call to action.
• Have minimum form fields 
• Remove all Footer Links if possible 
• Optimize for mobile
• Page load speed
• Improve page load speed

Improve Expected CTR (Click through rate)

• Avoid using short-tail keywords: If you use less than 2 word keywords then it’s obvious to have CTR less than 2%. Try using long tail keywords to increase your CTR and conversion rate. If you need more accurate long term keywords than look into your search term report, looks for those search queries are getting your conversions. Add them in your keyword list. 

Ex: if you use keyword like PDF to eBook, definitely it will attract different variations of the impressions but get less CTR, so try using PDF to eBook conversion. It’s more clear, targeted keyword. 

• Focus more on your benefits and solutions your product will add to user’s life than on sales pitch in ad copies. 
• Make Full Use of All Types of Ad Extensions: Using various extensions increases the size of your ads and makes them appear more relevant, 
• Use Title Capitalization in Your Adverts: Make your adverts stand out by using title case. It is proven to increase CTR. Which advert stands out most from the selection below?
• Be more specific in your ad copies
• Keep experimenting your ads with different call to action and benefits 
• Avoid Using Broad Match Keywords
• Use Keywords in Ad Texts
• Try dynamic keyword insertion in at least in one ad each ad group

Few more things to take a note about – 

As google mentioned in the recently released white paper on quality score, It’s important and helpful as a diagnostic tool and not a key performance indicator. 

1. Don’t pause, remove or delete the keywords just because the quality score is low. Google use it for a qualification process, it shouldn’t be using it for your qualification process, you take it as a warning indicator and improve your quality score. 
2. Google revealed that, each quality score you see in front of your keywords is not an exact representation of those in real-time quality score. Google takes other factors like users’ exact query, geographic signals, time, day, also in consideration every time, when every time real time auction happens. It provides a unique quality score number to your ads and keywords just make it more unique. Ex: if you see a quality score 6 in your account than in real time bidding google may give 6.209911000 number to it.
3. Make sure that your website is mobile friendly, because user experience matters a lot. 
4. Negative keywords play an important role in your account but it does not consider in quality score.