I know how to create custom stencils and shapes....what I haven't been able to find out is if it's possible (and how) to have my custom stencil w/shapes show up by default in the Shapes window/menu.
I would like to avoid having to go to > More Shapes > My Shapes and rather just 'stick' my stencil in that menu by default.
Is this possible?
Open stencils are something that's saved as part of a document's workspace settings. Ordinarily you would create a template that's saved with your stencil open. If the workspace option is included when saving, then subsequent documents (based on that template) will open with your stencil docked in position. Have a look at these two links for details:
Add a stencil to a template in Visio
Create and use custom templates