The industry standard for building a stone or stucco wall is to start with CMU’s (Concrete Masonry Units) and face them with the desired surface. CMU’s are easier than forming and pouring a concrete wall, but there is an easier option: ICF’s. ICF stands for Insulating Concrete Forms, and are basically a CMU made out of polystyrene foam instead of concrete. The process is largely the same- rebar is laid inside both horizontally and vertically, and the voids are filled with concrete. Since foam is obviously much lighter, the individual blocks can be much larger. There is a local company out of Napa called H-Forms, and the blocks they sell are 10″x50″ versus an 8″x16″ CMU- that’s 4 times larger. Instead of mortar, the blocks fit together like Legos and are glued together. And instead of a large footing, H-Forms can be supported by concrete piers, further cutting both the labor costs, as well as the environmental footprint, requiring far less concrete.
H-Forms also are more conducive to creating curved walls. Since concrete blocks are straight and rigid, they can only turn corners in 16″ increments. H-Forms can be scored and bent to create perfect arcs. Many curving walls are shown on their website here: http://h-forms.com/free-standing-and-retaining-wall-projects/