I used Faux Effects Sandstone painted with Modern Masters Metallic Olympic Gold, Faux Effects Crackle sizing went over that, then O'Villa plaster (and boy, did it crackle - a bit more than I had anticipated!) and then glazed with Burnt Sienna, Raw Umber and VanDyke Brown. I finished with a Flyspecking of VanDyke to add that finishing touch. It will be sealed with Faux Effects Colorseal and Duraguard.
The Duraguard is a more aggresive sealer so I usually use the Colorseal as a barrier coat between the delicate glaze and the finish topcoat.
Let's talk about crackle----it's one of those products that is hard to get just right. If you want large random cracks, put 2 coats of the size on in a random pattern (you can use a chip brush or a whizz roller - whatever you like, you just want it on the wall). You can make some areas slightly heavier than others - but don't get too carried away with that, you don't want your cracked plaster or your size to slide off the wall! If you want smaller cracks, just put on one coat of the size. For linear cracks, brush it on in one direction. My recommendation- always make a sample board and play with it before you go to the piece or wall you are going to work on. That way you know how much to add for a certain look......It let's you make the "mistakes" in your studio, not in a clients home.