Starting a new Bas Relief Sculpture

I have started a new Bas relief. It measures 18" x 24" x 3" deep and this time I am using Chavant LeBeau Touche - an oil based clay instead of the water-based clay that I had been using. It takes a lot of clay when working larger - I estimate that I currently have about 8 bars of clay ($10 each) on the piece and will probably have another bar of clay added before I'm done.

To reduce some of the clay, I did cut a foam core board to bulk out the base a bit. While I could have used tinfoil or foam to bulk out the girl and skim coated on the clay, saving $40 or more in clay, I find that I'd rather use the clay because I can carve deeper or make changes easily in the clay, but if there was a foil interior, I would end up digging into that foil and it is harder to make changes as I work.  
You can see that there are swirls in the clay - I started with older clay and bought some new clay and the dye lot was just enough different to show. A bit distracting while sculpting, but of course won't make a bit of difference when I cast and then patina the work.

Since this is oil-based clay, it sticks quite well to the board so there was no need to make the screw and wire network to support the clay as I did when using water-based clay in the first two Bas relief that I sculpted earlier.
Additionally, since this clay won't dry, it is easier to stop and start without worry about the clay drying out and it won't separate from the board, either.

I'm just in the blocking in phase now -she will be holding a larkspur flower and have wild horse mustangs in the background. I have never sculpted horses although I used to draw and paint them often so I am really looking forward to this!