Some of this is experimentation - some of it is attempts at making sellable beads!  All of these beads start with a base of opal yellow and then the copper leaf is added.
    

Here are some points:

• When you're working with copper leaf, you will see lots of boiling and sparks going on... but that's a good thing!  It will also look like it's not making color when it is, but you'll get used to what it should look like.
   
• I usually "disturb" the surface of the bead with a tungsten tool after I've applied the copper leaf.  If I do that, I don't have to add any enamel to make the blue/green come out.
   
• If you reduce the copper, it will turn red.  See the bead in the back far right.

The front left bead (larger view 1 and larger view 2) has some intense black on it - plus I had some copper leaf stringer that I had made (the "snake" patterns.) I put the clear all over the place to see what it would do.

Starting at the front right - this tabulated bead was the first experiment using clear (click here for larger view.)  I made horizontal stripes of clear to see what kind of reaction happens - the bright blue is NOT encased - I don't know why the clear didn't bring the blue out on this one like it has on subsequent beads.

The bead laying down on the far left is about three coats of copper on OY then lightly encased with clear.  I didn't disturb the surface, and before I encased it, most of the copper was still kinda black.  But when you put the clear on it, it turns that beautiful blue.  In the center of the bead, I raked around it, but it didn't make much happen because there was already enough surface disturbance going on.

The two beads with clear bumps are just plain ole, down and dirty put the copper on the bead, burn it a bit, make the dots and quit.

The bead standing up in back on the left has silvered ivory swirls and stuff.  This bead was heated for a long time - so the copper had plenty of time to really get absorbed.