Founder and CEO of Squirrly UK. Seasoned Entrepreneur, Growth Hacker, Advisor to a few startups and Professional Blogger at Adevarul Media Holding. Co-Organizes Open Connect Cluj and Antreprenori Cluj.
Google your top 3-5 competitors and create a spreadsheet of the top 10-20 sites they are featured in.
In your spreadsheet, include the name of the blogs, their URLs, the person who wrote the post, and also make a note of how many of your competitors they covered. If it's more than 2, that writer is probably specifically covering your niche/industry.
Check out Alexa, Quantcast, GPR, etc. for these people, as well as soft metrics (like the ones whose articles kick ass and who are offering a lot of value to your industry).
Get to know them on twitter for a few months, providing helpful information or retweeting their articles (or commenting on them), BEFORE you need anything from them. That means that you're sending them information that has nothing to do with your startup. Also make sure to read all of their articles, so you have a better idea of what they like or don't like to write about, and any other nuances.
Once you decide you want to talk to them, instead of sending a press release, try sending a short note (3-5 sentences), making sure to explain what's in it for them and why you are relevant.
If you MUST send a press release, include a personalized 3-5 sentence note in your email.
TechCrunch may not be the be all and end all for your startup. Other options that may get more traction include local tech blogs, blogs specific to the industry you're in, etc., even if you're just using them as a starting point to begin building up your media presence.
Make sure your bio, pics, etc. are media friendly.