1). Community Creation in Social Networking Sites: Try to become a member of the most popular social networking sites like Orkut, Myspace, Facebook, Linked In, Ecademy, etc., and create a profile of your own. Extend your network online, get connect with your friends, share things with each other, and promote your company/website to build an online reputation.
2). Blogging: Write a blog of your own for your company/website and include lots of unique content. promote your blog in blog directories and blog search engines.You can also promote your blog/website by posting comments in other service-related blogs which allow links in the comments section that are crawlable by the search engines (these blogs are commonly identified as Do-Follow Blogs).
3). Forum Postings: Create a forum/online discussion board of your own and start a discussion or share topics with your friends. You can also post/reply to a thread in other service-related pre-existing forums that allow links in your signature which can be crawled by the search engines (aka “Do-Follow Forums”).
4). Search Engine Submission: Submit your website to the most popular search engines like Google, Yahoo, MSN, Altavista, Alexa, Alltheweb, Lycos, Excite, etc., to get listed for free.
5). Directory Submission: Submit your websites to the topmost quality directories like DMOZ, Yahoo Directory, ZoomInfo, One Mission, Pegasus, etc. Choose proper category and place your links in top quality websites.
6). Social Bookmarking: Social Bookmarking is yet another powerful way of promoting your website, but nowadays most people are spamming social bookmarking sites without knowing how to use them. Do some social bookmarking in popular bookmarking sites like Digg, Delicious, StumbleUpon, Propeller, etc. You should be very careful while doing this and you must properly handle the tags which are very essential to broadcast your news on a wide area network. This may increase your website traffic based on how effectively you have participated.
6). Link Exchange: Exchange links with service-related websites (this is commonly termed as Thematic Link Exchange) that can help increase your link popularity, which is a major factor of Google’s PageRank algorithm. Beware of Black-Hats while doing exchanges.
7). Link Baiting: Suppose you have copied/published another website’s news or content in your blog/website. Don’t forget to place their website link as a reference. Do it for others and, if your content is trustworthy, let others do it for you. This is another way to increase your link popularity.
8). Cross-Linking: Link to internal pages within your site wherever necessary (this is commonly termed Internal Linking). This increases your internal link popularity ,which is another major factor of Google Page Rank algorithm.
9). Photo Sharing: Publish/share your website product pictures and make them public. Let your friends see them and comment on them too, which will help drive traffic towards your website. Do this in major photo sharing websites like Flickr, Picasa, Photo Bucket, Picli, etc.
10). Video Promotions: Like with photo sharing, you can publish/share your product videos, expert opinions, and reviews of your product and make them public in YouTube, Metacafe, Dailymotion, etc.
11). Business Reviews: Write reviews about others businesses or ask your friends/clients to write a review of your business in major business review sites like RateitAll, Shvoong, Kaboodle, Stylefeeder, etc.
12). Local Listings & Yellow Pages: Instead of going global and facing huge competition, make your website local so that search engines can easily view your website and fetch the content. This will help you to reach a targeted audience. Submit your website to Google Local, Maps, Yahoo Local, Yellow Pages, Superpages, Hotfrog, etc.
13). Article Submission: Write articles of your own and submit them to popular article sites like Ezine, Go Articles, Now Public, Buzzle, etc. This will help you to attain some deep links for your website (though it’s usually a slower process).
14). Press Release Promotion: If you are a business/service provider then go for PR submission in popular PR websites like 1888pressrelease, Open PR, PR Leap, etc. This will help you to publish your site in Google News.
15). Classifieds Submission: Do some classifieds submissions to advertise your products for free. Try Craigslist and other major classifieds sites like Kugli, Myspace, iMadespace, Vivastreet, etc.
16). Social Shopping Network: If you own an e-commerce website, this is a good strategy for advertising and easily branding your products for free. Submit your products to Google Product Search, Yahoo Online Shopping, MSN Online Shopping, and other major social shopping network sites like Kaboodle, Style Feeder, Wists, Five Limes, Buzz Shout, Ohmybuzz, etc.
17). Answers: Participate in Answers by asking and answering relevant questions and placing a link to your website in the source section if necessary. If you don’t spam, this is another great way to increase your link popularity (Yahoo Answers, Cha-Cha, Answer Bag, etc.)
18). Document Sharing: Share your website documents like business documents, information brochures, and slides in Google Docs, Slide Share, etc. This will help you brand your website.
19). Social Media Posting: Be active on Social media channels and post quality content there to engage your users. Also try to take reviews from your user and increase number of followers to your business page and business profiles.
Source : http://www.quora.com/What-are-the-best-dofollow-backlinks-in-2015-to-bring-site-on-top-10-organically