If you find yourself focusing too heavily on one type of link source, you could be limiting the success of your SEO. First off, if your favorite link building tactic is ever labeled as black hat by the search engines (much like link exchanges were) then the bulk of your links are now on the wrong side of the Webmaster Guidelines! By taking a diverse approach to your link building, you are demonstrating a commitment to white hat SEO and are protecting your site from any future changes in the search engines’ algorithms.

I use to do Blog creation in Niche site, Forum posting, Article Submission, Local Listing Submissions, Google Map Reviews etc.

My is forum postings.

External links are helpful but you have to considers some point that must be followed. If you are putting external links that place it at proper and appropriate section. Do not use external links in the body of the article. Place the links at the external links section or in the resource box.

Link Wheel, Link Trundle, Profile link building are producing effective results.