1.Page Titles
2.Meta Descriptions
3.Meta Tags
4.Heading Tag
5.Alt Tag
6.Internal Linking

On page Seo Tips are:

Url Optimization
Image and Video Optimization
Meta Tags
Content optimization
Strong Internal Linking

Some On page Tips

1.Create the Quality Content
2.Create the Meta tags
3.Create the Robots txt file and Submit the web master tool
4.Create the XML Sitemap and Submit the web master tool
5.Make the Responsive

Content length (word count) is key. Shift to semantic search only increases this. don't try to be too clever writing specifically for SE, write quality content which answers questions. Semantic search is only going to increase with voice driven search requests.

Some of the important things to consider in On-page optimization;
1, Keyword Research and Analysis
2, Title tag Optimization
3, Meta tag Optimization
4, URL Structure
5, Page Content
6, Important HTML tags
7, Anchor Text Optimization
8, Image Optimization
9, H Card Integration
10, Robots.txt Optimization
11, XML Site map Creation and Submission