If you’re not yet running version 9.12, wait for it to be rolled out around the world or grab the APK and update manually. Custom names for places is an upgraded version of Stars (which is still around). You can give any location on the map, a name (which, of course, is private). Even an unknown location that doesn’t have a name in Google Maps. You can then easily search for this place in the Maps app. But right now, Google Now’s Navigate to.. command doesn’t seem to be working for custom names. I think this is much better than Stars and would be really helpful for something moving to a new city or when on a vacation. To create a custom name, all you have to do is either press and hold on the location to drop a pin or search for a place.
Either way, you want to pop up the information card. Now, you’ll need to tap the three-dotted-menu button in the top-right and select Edit name. Type in the name and you’re done.