The lace work is done by copying a pattern in my references for the figure. Since the lace involves a repeating pattern, I maked off some straight reference lines with a pencil and started by making the largest elements in the pattern first . I tried to make sure they were lined up properly. Once these first elements had dried, I started on the smaller parts in between and just continued around filling in the basic pattern details. As for the sculpting, I applied a small blob of putty in about the right size and shape and then cut it down and shaped it with a needle tool and x-acto knife. Final smoothing with water.
I've found that MS that has been mixed and is about 20 minutes old seems to work best as it still sticks to the dried putty well and can be shaped easily, but has gotten a bit more firm so that it can be more easily detailed. I hope this helps.