Here are a few basic tips/reminders you can try to improve your income from Adsense:
1. Use the most popular Adsense ad sizes, experiment with the new, bigger ad sizes and test their location on the page.
Picking adsizes that are popular with advertisers, you’ll get more competition for your inventory between advertisers and a higher cpc, so always keep plenty of wide ‘stock sizes’ on your site. The most popular ad sizes are popular with advertisers for a reason, they work better. A wide ad is better than a tall ad. This is because visitors read in chunks of a few words at a time and wider ads make more sense to an ad viewer (Adsense calls these word chunks ‘thought units’). Large rectangle 336×280 is the most popular for this, and it’s popular with advertisers, but there are newer ad sizes you should try. And even create your own, but always try them in new positions within your content to test what works best and in conjunction with item 5 below.
2. Quality Content attracts Quality Visitors
Sounds obvious, but it’s still the number one thing you can do to improve your site’s authority score and to earn more from Adsense ads is to add more, high quality, original content. The reason advertisers are buying clicks from users on your site is because your site’s visitors are highly engaged with your content. It’s not that your Roman History site will necessarily be showing ads for sandals 🙂 – it’s more that the higher the engagement with your audience, the more likely the visitors are to be paying attention enough to see an ad and think about clicking on it. Visitors from organic search and from your email list are the best quality visitors you can get. Get more of them. The targeting of the ad is Google’s business. Your site’s Traffic Quality / Visitor Quality is yours.
3. Don’t kill the Goose that lays the golden eggs! Measure and improve your User Experience (UX) Metrics and keep monetization and UX in balance.
You want your ads to be seen, but you don’t want to spam out your users either. So how do you do that? Having too many ads ‘above the fold’ (the immediately visible portion of a typical screen size) is bad and will damage your site. So how many is too many? Google’s advice on this is to keep your ad density from overpowering your user’s attention away from your content.
Here’s how we do it at Ezoic – monitor and improve your bounce rate, page views per visit, or average session time by testing new layouts and ad positions at the same time. If you balance your ad income metrics (income per thousand visits is what we use at Ezoic) against your UX scores for your site, then you can keep your site from being too ‘ad heavy’. If the UX metrics are improving and your income is also up – you know you’re striking the right balance. This of course also applies to Mobile as well as desktop.
4. Keep up to date with Adsense best practice and keep it clean!
As my Grandmother used to say ‘Honesty is the best policy’. Don’t do anything to kill the quality of your advertisers’ clicks (or kill your content quality).
Avoid any ad implementations that could lead to accidental clicks and ALWAYS keep within the Adsense guidelines. Keep your content family friendly, always attribute any quotes or content that isn’t original, don’t click on your own ads and never, ever be tempted to try anything that could dilute your traffic quality. You can be sure Google’s seen it all before and with the data they have access to – they will catch you.
5. Methodically Test your Fonts, Colors, Borders.
Bigger font sizes work best, Google’s default palette is a good one to use, but test, test, test your fonts, colors and borders. It’s not the case that one method works for all sites. 
The quality of your upstream traffic (whether most of your users are coming from Google, Bing etc or if they are arriving on your site from Facebook) affects how the page should be laid out and what the ads should look like.
Summary: Test, test, test!
In our experience if you keep testing layout and ad position placements on desktop mobile and tablet, you can generate 50-250% more income from exactly the same content (whilst improving UX). All you need is the data, time, patience and tools.
