So other than taking time and sculpting an entire object to make stitches, is there a quicker way to do it? Blender should make a stitch sculpt though if there is no quick way.
With version 2.78, you can now draw curves onto surfaces.
To use it:
Add a Path curve in object mode (Shift + A >> Curve >> Path).
Enter into edit mode (TAB).
T to show the Tools panel.
Under the Options tab set your Projection Depth to Surface.
Under the Create tab click Draw Curve or alternatively Shift + A >> Draw Curve.
NOTE: you can play with the Tolerance under the Options tab to get settings to your liking. After creating your desired curve, delete the verts that make up the original path.
Create a thread mesh design.
Add an Array modifier to your thread mesh, setting its Fit Type to the curve object.
Add a Curve modifier to the thread mesh, setting its Object to the same curve object in the Array modifier.
For me, I picked the start point of my curve as being the origin of the curve, and set its position to the origin of the thread mesh, then played with the Constant Offset of the Array modifier.
Here's was my results:
My normal approach is to load up an alpha texture and subdivide my sculpt pretty heavily. I use Rake for the texture, and set spacing by trial and error here depending on the image used - this one was just from rendering a cube from top ortho view with some bevel on the edges. and the image used is