Trimming accents are usually the last thing people are thinking about when they are designing the exterior of their home. There are so many different ways to do it. Many do stucco bands or hardie bands but there are other masonry options that you can choose from as well.
Like in the photos above, some prefer to use trim stones and keystones, others prefer soldiering the stone they are already using on the rest of their home.
Some use brick.
And typically when you are soldiering your stone, most people use corner pieces to wrap the 90 degree angles. With corners, there is usually one side that is longer and one side that is shorter. When using them for a trim design you can use the longer side facing out, the shorter side facing out, or you even have the option to alternate, longer shorter, longer shorter.