Build a great team and product and/or show traction and market potential (size, genuine problem you're attempting to fix). When pitching, describe what you do in a single sentence so that investors get it right away.
As I say, it's in stealth :-)
1) If they are European-based (I write for TechCrunch Europe)
2) The have real news e.g. a launch, raised funding, an interesting new feature or change in strategy etc.
3) I get the story *first*