Crackle glass effect - do's and don'ts

I have been very intrigued by the crackle glass technique I've been seeing quite a lot of lately.

I looked it up on Splitcoast and found some nice tutorials on the subject and this was what I managed to come up with.

 

I used this rad drawing I found online of the bone structure of Hello Kitty.

I decided to 'age' the image prior to adding the crackle glass effect.

I only figured this out AFTER I ruined a few images by adding the color to the piece after I cracked the glass.

   

Don't care for this look at all.

This one was kinda cool, but I still prefer the color added to the image before the crackle.

I used a minimum of 3 layers of the Ultra Thick Embossing Enamel. Then I popped it in the freezer for a few minutes, and when I took it out, I immediately started cracking the image. Once it begins to warm up, it stops cracking and just tears the paper if you're not careful.

Really cool technique. It would be really sweet with a stained glass-like image.