Go to local events or Meetup events and connect with bloggers in your industry. An example of an event I run to connect with bloggers and people in the online marketing word is: http://www.meetup.com/Online-Marketing-Sydney/. Make friends first and then try to gain guest posts later. I am not really a fan of websites which are flooded with guest posts one after another; it is the type of thing which Google is just waiting to target.
Companies that employ overly aggressive techniques can get their client websites banned from the search results. In 2005, the Wall Street Journal reported on a company, Traffic Power, which allegedly used high-risk techniques and failed to disclose those risks to its clients. Wired magazine reported that the same company sued blogger and SEO Aaron Wall for writing about the ban. Google's Matt Cutts later confirmed that Google did in fact ban Traffic Power and some of its clients.
Now, it is not that these sites are not interested in Google users. In fact, they have hired us to help them increase their share. However, they are getting so much traffic from sites like Facebook that it seems there is less urgency about attracting this traffic and less willingness to change the site to meet organic standards. Not long ago, sites would urgently and unquestioningly abide by Google’s standards to court that traffic.