There really aren't any shortcuts around PR, but there are better ways to go about it than just emailing a standard, boring and long email to writers on TechCrunch.
The best advice I can give here is to not hire any PR people as a cash-strapped startup, do not send expensive PR releases and trust me, your story is not as exciting or original as you probably think it is.
All that being said, PR can be used to your advantage if you have a compelling background and you successfully target the niche bloggers and press.
PR is a bottom-up economy. A little, no name blog picks up a story in their niche, and if it's sexy enough it will continue to ascend the ranks and larger publications will take notice. There's no guarantee, of course, but you can position yourself for these things to happen.
Remember, blogs/publications only care about one thing: click-throughts. Controversial, compelling titles that make you click-through is their business model.