How do I create a custom Angstrom image?

Hey Guys,
How can I create a custom Angstrom image? Specifically I am using console image as a start and building on a local machine. I want to be able to add specific packages for a custom build. For instance I want to be able to add SDL libraries and cross compile against the headers.

I did google a bit and most of what I found was fairly old and for OE classic.

Any pointers would be greatly appreciated.

Mark