wow these are so beautiful! would you post a tutorial at all? and what guage wire do u use?Like most people, I started by using this tutorial: http://www.beadstudio.com/info.php?a=613
But after a few months of practice, you kinda find your own rhythm of what works best. As for wire, it depends on the look I'm going for. Generally 16 gauge outside and 24-28 gauge for the branches. It's really a trial-and-error thing because it took me a dozen or so before I really felt more comfortable with the process.
As for the nests...? No tutorial just because I don't have a real "set" way of doing them. I'm still perfecting them (I've made about seven total so far so I'm still learning how to do it.) I didn't use any tutorial, I just kinda made it up as I went along. As for gauge, again, it varies. I'm using anywhere from 20-28 gauge depending on the look I'm going for.
Hope that helps somewhat!