A Private Blog Network (PBN) is a network of authoritative websites used to build links to your money website(s) for the purpose of ranking higher in the Google search engine.
Most Effective Off page activity are
Article submission
Blog submission
Classified submission
Local Business listing
Images sharing
Video sharing
Info-graphics submission
Guest posting
Forum profile creation
If you want to Improve Keyword ranking of website. DO SEO Off page Activity are
Article submission
Bookmarking submission
Directory submission
Question answering
Images sharing
Video sharing
Info-graphics submission
Guest posting
Forum profile creation
Effective way optimize site.
Focus on Youtube SEO
Improve Site Speed
Build high Quality
Content posting
Local listing and SEO
Guest posting
There are many way to Optimize Website. First do seo On page activity are
Meta title
Meta description
Meta keywords
URL Structure
Sitemap.xml...
SEO On page Technique Increase Website ranking.
On page Techniques
Title, Meta Description, URL Structure, Internal linking, Alt txt, 301 Redirection, 404 Error page, Sitemap.xml, Robots.txt, Heading tags, Content etc.