IF you think about ON page SEO then these following Questions are arises in Our mind.
Content
Quality: Are pages well written and have substantial quality content?
Research: Have you researched the keywords people may use to find your content?
Words:Do pages use words and phrases you hope they will be found for?
Engage: Do visitors spend time reading or “bounce” away quickly?
Fresh: Are pages fresh and about ”hot” topics?
Thin: Is content “thin” or “shallow” and lacking substance?
Ads: Is your content ad-heavy especially ”above the fold”?
HTML
Title: Do HTML title tags contain keywords relevant to page topics?
Description: Do meta description tags describe what page are about?
Headers: Do headlines and subheads use header tags with relevant keywords?
Structure: Do pages use structured data to enhance listing?
Stuffing: Do you excessively use words you want to be found for?
Hidden: Do colors or design “hide” words you want to be page found for?
Architecture:
Crawl :Can search engine easily “crawl” pages on site?