do you think backlink from which the most effective way to blog, whether backlink from social bookmarking, blog commenting, forum profile, or where? thanks
You ultimately want a good mix of links and it should look as natural as possible, so you want a mix of nofollow, dofollow and ideally, high-authorithy links (e.g., sites with an established presence / PR2+). There are some that would recommend having a mix of reciprocal and one-way links to ensure that your site is not pagerank sculpting (e.g., keeping links structured/flowing internally, with little links pointed outwards to external sites).
You can fallow any linkbuilding methods but try to get backlinks from your relevant and highpagerank sites to get quality backlinks to your site.
Guest blogging and back links from web 2.0 sites are considered as most effective as their is minimal chances of getting these sites penalized.
Back links from forums, press release, articles submissions as well as from video submissions are most effective.
A mixture of them is the best strategy! Your website should have both dofollow and Nofollow backlinks, otherwise this would look unnatural according to Google and the final results would not be very good... For example, guest blogging and Social Bookmarking backlinks (dofollow!) are a good source of quality backlinks. Also if you have time, article and forum marketing are another good SEO strategy (it's not a problem if the forum backlinks are nofollow)... Another source for ONLY nofollow backlinks are blog comments, but 5-10 blog comments are ENOUGH per week for your website ... And always do your SEO MANUALLY!!!!!!!!
According to me, Industry based backlinks are more important to your website. You could see that after Google update