You van follow these things
1. On Page
1.Make sure redirections to your website everything with www.
2.Update XML site map and HTML sitemaps.
3.Create robots.txt.
4.Write relevant Meta tags (Title and Description only) for each page.
5.Use keywords should be in title.
6.Write Header tags H1, h2, h3 primarily.
7.Update ALT tags to all images.
8.Give internal linking to relevant long tail keywords.
9.Create blog snippet on home page footer.
10.Put copyrights note in footer.
11.Use schema code for all images and videos.
12.Create videos-sitemap.xml and submit in Google webmaster tools.
13.Update contact address and phone number
14.Make your site in responsive design
15.Improve your page speed between 3 to 4 seconds.
16.Check broken links and fix it.
17.Check HTML improvements in GWT and update.
18.Update social icons in your website
19.Apply Google authorship (still it was value in Google)
2.Off Page seo link bulding
Link building is not spam. Without links there is no SEO. Here are important link building techniques for 2015.
Search engine submissions
High authority Local directories submission
Local listing
High authority social bookmarking sites
Google plus regular posts
Ezine article submission
DMOZ approval (Mandatory)
High authority presentations like scribd, slideshare etc.
Info graphics
Blogspot and wordpres blogs creation and postings.
PDF submissions (post fresh content only)