Good practices in Magento theming

There are a number of points that a good Magento 2 theme will typically abide by:

• Take advantage of Magento theme inheritance to develop new themes
• Follow the basic directory structure proposed
• Restrict any .phtml (Magento template files) to just those that have been changed for use with the custom theme

Adhering to these guidelines of Magento theming makes it easier to upgrade your Magento installation without making changes to your theme files.