There are so many favorites of mine. Kalera's Ask Me Anything where she generously shared recipes and tips and just anything is one of my favorites.
But I have to vote again for Sara Kay's Blue Bead thread.
http://www.lampworketc.com/forums/showthread.php?t=235
Here's my reasoning and, not coincidentally, my tip.
I've tried this recipe a few times before Sara passed and just couldn't get it right.
After she passed I read the thread start to finish again and then went to my studio. I tried it all over and didn't get the result I expected, but it was interesting. So I took the recipe and used different colored base glass. Another cool bead, so I continued and ended up with a little set of different color beads made the same way.
This really drove it home that I have to let the glass do as it will. If I fight it, I'm never as happy with the result as I am with the results I got when I started with Sara's recipe and followed where the glass led me.