According to my experience, "Content Marketing" is the best SEO strategy in today's modern SEO. As we all know Content is King and Google also loves to crawl quality content every time.
1- Do social bookmarking on regular basis and post about your website on regular basis and enhance your friend circle.
2- Do business listing
3- Post comments on blogs.
4 - Participate in forums
5 - Participate in question answer sites to collect trusted links.
6- You can also hire an expert from SEOclerks.
First of all you should work on OnPage Seo then you should to start build back links on Forum posting, directories submission and create a free web blog and submit unique new article with your website link..