According to the Google the back links from guest posting and article submissions are also considered as spam links, then now what are the ways remain for creating the back links. What is your strategy for creating back links???
Private blog network links all the way. Has been working like a charm and will continue to work. On top of that, web 2.0 and social bookmarks for anchor text diversification.
Who told you that links from guest posting and article submission are considered as spam. Matt cutts clearly said that if you have post your stuff in quality based then Google will never discourage you. Thank you.
The links from article sites are not classified as spam that what my SEO experience can tell. None of my sites drop, I use a lot of article directories to publish content and try to get attention from new customer.
Guest posting definitely doesn't give spam backlinks as long as you are posting on quality sites. Mass article submissions aren't as effective as they used to be and I don't really bother submitting to article directories any more. For me the best way to build backlinks is commenting on high quality blogs. I've ranked many of my niche sites doing this alone. After that I do the occasional guest post, press releases, and forum posting (if there's a relevant do follow forum). Tiered backlinking still works well - create web 2.0 sites that link to your money site and then build backlinks to the web 2.0 sites to give them some extra 'juice'. Since the last few Google updates you can get by with far fewer backlinks, but they need to be high quality.