[jimejim]

Along with what everyone else mentioned, if you like podcasts, this one gave me some good insights along with the blog:

http://www.sustainabletdd.com/

One aha moment for me that's talked about here is to treat your tests more as a form of documentation and specification of how to use the system. They talk about how you should even do some basic tests to confirm enumerations and constants in the system as a way to be clear about their use.

You don't always have to be as thorough, but the mental shift from test to specification was helpful for me.

Edit: Unfortunately, if you download this podcast it's a bit out of order, so you want to read the blog and use it as a guide for which order to listen to things. They're in the process of writing a book about TDD and this blog is part of their process.