The last time you visited a restaurant, hotel, bar or kids' fun park, did you bother to leave a review on Google Maps? Doing so is about more than just giving other visitors an idea of what to expect -- it also lets Google give you more customised recommendations of where to visit next.
You can see places you've recently been to by heading to your timeline page and following the links at the bottom of the screen. Click on a place name to view it, open up the additional menu (three vertical dots) and select Place details to bring it up on Maps. Click Write a review to share your thoughts and a star rating out of five.
To get the benefits of your reviews, head to somewhere new on the map, search for a particular type of place, and if there's an abundance of hits to sift through then the ones that suit your tastes are shown more prominently with larger icons (other alternatives can still be brought up by clicking on the red dots). Places you've already visited and rated are shown in orange.
The same process works on the mobile apps for Android and iOS too. Tap on a place card, and scroll down to leave a review, then when you hit the Explore option (at the bottom of the main Maps screen) your recommendations are going to be a lot more personalised and (theoretically) useful. If you're exploring a strange place, you can find spots to visit that you might actually like rather than just those that are highly rated by a bunch of strangers.