Before Applying for Adsense or any other ad network consider these points :
I am sharing these points based on my experience with ad networks for more than a decade.
1. Use a website / blog that is atleast 1 months old. In some cases the minimum duration is 6 months.
2. Write atleast 20 Unique Articles (to avoid insufficient content issue) with a minimum of 300 Words Per Article.
3. Provide an About Us, Contact Us pages which will give more authencity to your website.
5. Use images in your articles for better user experience and use compressed images to ensure faster page loading.
6. Add your website to Google Webmaster, Bing Webmaster, etc and submit sitemaps as well.
This will help your website in getting search engine indexing. Properly indexed websites have better chance of approval in ad networks like adsense.
7. Test your website for broken URLs.
8. Check your website for grammatical errors and correct them.