If you are doing templates for legal papers, you need to learn the method set forth in Shauna's page. By themselves, using the buttons on the Ribbon as suggested by Microsoft will make a mess of numbering. Just sit down with a new document/template and take the steps given by Shauna Kelly, one by one. You have to do them in order and do all of them. You need to set up all of the levels in one go.

Once you have it, you can save a template and use that template as the basis for new documents and for new templates.

(I am a lawyer.)

You may also find the following helpful; it has a section on cross-references:
Complex Documents