For structural purposes and economy, avoid stack bond!! The only benefit of stack bond is the alignment of the cores. In some limited areas of the U.S. and the more advanced international masonry markets, core alignment may be automatically be obtained by using one core units with cross webs at 8" on center.
According to ACI 530, "stack bond" is referred to as "other than running bond". Running bond requires that the units lap by 1/4 of the units length.
For a 12" wall (assuming 16" long units), you can still avoid the techincal code provision imposed on stack bond by using all 12x8x16 units if you have alternating courses. The 4" difference between the width of a 12" block and the length of the 16" block below it provides the necessary lap. Some people do not appreaciate the appreance of a 4" "offset bond" even though it is not classified as a running bond.
As MarcbSE said, in most areas you can routinely get "L corners" in 6", 10" and 12" thickness that provide a running bond appearance wising just one unit. This is the preferred detail.
If these units are not readily available, you can use an 8x8x16 unit at the corner and use 2 concrete brick to fill in the inside corner. The appearance is still the same as got get with the L corners, but you have the minor inconvenience od not doing it with just one unit. This requires no special units and be accomlished even in unsophisticated masonry markets.
For some architectural units and critical application, using the brick may be preferred or even specified.