The Style Gallery appears on the Home tab in Word 2016. You probably ignore it because it’s chock full of mystery styles you don’t use, but the thing is entirely customizable. If you’re going to the trouble of creating your own template with your own styles, why not modify the template so that you can put your styles in the Style Gallery?
Start by purging styles you don’t want in the Gallery:
Click the down-pointing arrow to reveal the entire Style Gallery.
Right-click a Style tile.
Choose the command Remove from Style Gallery.
Poof! It’s gone.
To add your own styles, obey these steps:
Display the Styles pane.
Press Ctrl+Alt+Shift+S, which is Word’s most memorable keyboard shortcut.
Right-click one of your styles.
Choose the command Add to Style Gallery.
That’s it!
The style isn’t removed from the Styles pane. It’s still there, but it also shows up in the Style Gallery, which you might find more useful.