Build a posting relationship with your blog targets.
I use a shock and awe technique that doesn't violate any rules, however it take them by total surprise if they find out how you did it. By this point, it is way too late though.
The point of this is to use it to build my own pr and authority value to the SE.
Post articles and content on your site, reflecting references and comments on blog posts made by this target blogger, giving a backlink back to his/her site and post from your site.
This will make you charge your content as well. It isn't stealing/scraping or swiping if you give create in a related niche post. The guy is getting a free backlink from you, like he is going to complain.
Go to his blog and post 10-12 quick but sincere and quality comments, making the first one a reference to how you just found the author's post and gave them credit for it with your readers, pumping their ego a bit, then giving your extended perspective on the posted information, method, etc...
They haven't turned one down from me yet. If you want to boost the stability of it even further, send them an email or post in their blog, asking them right there on the spot, giving them the link to your site in the same method.
They won't reject you because it is a free backlink and possibly more traffic to their site, therefore, you both reap the rewards. I personally do this all the time and have NEVER had a rejection from this method.
Just be sincere and post stuff that will benefit both of your sites. Ifyou link back to crap, you are toast.