Save your custom template by clicking "File" and "Save As." Enter a filename in the "File Name" field. Click on the "Save as Type" down-arrow and select "Word Template (DOTX)" to save your template.

Add a text box to the card by clicking the "Insert" tab, clicking the "Text Box" button on the ribbon, then choosing "Simple Text Box." Word adds a text box to the template and a new orange "Text ...