How do you go about advertising your startup?

How do you advertise your startup? I've noticed a number of people use HN for this but I want to know what people are doing and what works? Also what doesn't work?

I know most people will say it depends absolutely on your product so include some information about what it is, I'm interested in all of them.

I'll start: An (in hindsight very crappy) email client on the web. Methods: - press releases to techno blogs etc - invite your friends incentives - Facebook twitter etc - blog posts

No great success however this is mostly due to the product. I was young and naive.