Below are best ways to add more quality backlinks to your site:

1. Comment on “DoFollow” blogs.

By default, WordPress blogs have the HTML “NoFollow” attribute on links that point away. Blogs do this to prevent “link bleed” and prevent spammers from inundating their blog with irrelevant comments. DoFollow blogs, on the other hand, don’t have this limitation — and you can use this to your advantage to get backlinks.
Just search on Google: dofollow blogs list

2. Q&A Platforms

Main perk of Q&A services in terms of your website’s SEO lies not so much in backlinks creating, but in increasing brand visibility and direct targeted traffic flow. Usually, Q&A websites automatically set rel="nofollow" attribute for all links, but it doesn’t mean that such links are completely useless for your website.
Here are several Q&A services that deserve special attention:
· Quora. Large international service with a huge community and amount of professional questions (and answers, of course).
· Yahoo Answers. Popular Q&A service developed by Yahoo search engine.

3. PBN backlinks

PBN is No1 way now to get backlinks and rank higher and faster on Google.
A Private Blog Network (PBN) can be a site or a group of sites (domains) used to rank your site higher in search engines.
The domains used for this are sites that used to be real sites before, but were either sold or left to expire.

4. Create SlideShare presentations.

Slice one of your infographics into pieces, or repurpose one from your last speaking gig. You can put these up on your blog, in your website's resource center, or even on a SlideShare account for more links.
Keep in mind that the most shareable presentations are the ones that are the most compelling. That means great content and great design.
How to: Just create a good powerpoint file and upload it to slideshare .net

5. Look for broken link building

David Zheng, editor in chief Crazyegg describes that, you must be aware of broken backlinks because it would eventually hamper your site. According to the process, each link on a site links to another online page. But as websites keep moving their content around, many times these links “break,” or they no longer exist. Therefore, when a user clicks on a broken link, they come across a message ‘404 error page.’
When this happens, search engines cannot index or crawl websites. Therefore, you should concentrate on broken link building and build valuable links. The method involves finding broken links and identifying the content they originally referred to. Finally, you can offer the site the chance to replace their broken link with a valid link to relevant content.

6. Guest posts

“Guest posting” is the practice of contributing free content to another website or blog in exchange for a link back to your own site.
These links can either be placed in the author bio section or used to cite information within the body of the post.
This has long been a popular link building method since it’s a win-win for both sites: One gets free content to share with their audience, while the other earns a high-quality link.
Just search Google by phrase: your keyword & “guest post”
For example: diet tips & “guest post”

7. Forums

Manual blog commenting is one of the most simple and widespread link building techniques: all you need to do is to find and filter topics relevant to your niche and then start leaving comments.
Before you start working with a certain forum, you need to check:
· amount of organic traffic
· regular activity
· who ‘lives’ on a forum: real users or link builders
Before writing comments, take forum rules into account: some of them say that you need to get some reputation before placing links in your comments. Violation of the rules can entail temporary or even lifelong ban.

8. Social media

This is something of an extension to the above section on Google+, which we felt deserved its spotlight. Other social media platforms can be just as important as a platform to generate backlinks for your site and to promote your content. In fact, it’s so viable and popular an option that people have made a career out of being Social Media Marketing Managers.
You don’t have to hire one when starting out of course because you should be able to run your social media platforms by yourself without any difficulty, but in the long-term, you’ll probably turn to one too.
How it works is this: you create a Facebook page for your business, where you can interact with users, promote your company, and share your content. You’ll also find yourself sharing content from other sites, of course, and they’ll usually return the favor. Your followers can get regular updates on new content, products, and promotions, and they’ll be able to share your posts with their friends to—creating a ripple effect of backlink opportunities.
The same can be said for Twitter, which we already mentioned as a great platform for finding opportunities to guest post on other sites. Another popular trend (more for product oriented businesses, although service providers should also consider finding ways to utilize the platform) is Instagram, which will allow you to promote your brand and share advertising campaigns such as competitions with a wide range of followers.

9. HARO

HARO (helpareporter. com) is an online service for reporters helping them to quickly find experts in different fields of expertise and get professional feedback. Service allows registration for both reporters and experts, so you can register as an expert to be mentioned by reporters in their publications.

10. Give interviews

There are websites in virtually any niche that run interviews with experts. If you’re not well-known enough to be invited, reach out and pitch the interviewer on why they should interview you.
Sites that run such roundups are always looking for great content, so you have an okay chance at getting accepted. Along with your answers, you can also link out to your website.
To find websites that run interview roundups, you can search for these key terms:
· Your keyword + roundup
· Your keyword + interview

11. Broken link building

A lesser-known way to build backlinks is called the broken link building technique. This involves finding 404 errors or similar problems on a blogger’s website and politely telling them about it.
Because you’re doing them a favor, they might reward your help by linking out to your website. These backlinks are commonly found on resource pages where bloggers link to third-party sites.
You can easily identify broken links using the Google Chrome Extension called Check My Links. After finding these issues, reach out to the webmaster and tell them about the problem. Give them direct instructions and make it easy for them to identify and fix the mistake. Then suggest your website as a resource to replace the broken link.

12. Donate.

Yes, you can earn backlinks by donating to nonprofit organizations. This method is quick and straightforward. All you have to do is find websites in your niche that accept donations and link back to sites that have donated. Simply submit the amount of the donation you want to make and write your website URL.
Finding these websites requires some searches in Google. These are some queries that usually give good results:
· contributors page + donate + your keyword
· donation + contributors + your keyword
· contributors page + your keyword