(Year-old news from the group comments; probably still relevant and helpful, so I'm posting a copy in a more visible place.)
"Google tracks you even if Location History's off. Here's how to stop it" (Wired, 8/13/2018)
"... the search giant still tracks you every time you open Google Maps, get certain automatic weather updates, or search for things in your browser. There's a way to stop it—but it takes some digging.
The problem affects anyone with an Android phone and iPhone users running Google Maps on their devices..."
Turning off Location History is not enough. You also need to turn off Web & App Activity.
"Sign in to your Google account on a browser on iOS or your desktop, or through the Android settings menu. In the browser, access your account settings by finding Google Account in the dropdown in the upper right-hand corner, then head to Personal Info & Privacy, choose Go to My Activity, then in the left-hand nav click Activity Controls. Once there you'll see the setting called Web & App Activity, which you can toggle off.
On your Android phone, go from Google settings to Google Account, then tap on Data & personalization. You'll find Web & App Activity there."
Read more, including information about Google's deceptive design practices and statements, at the full article: https://www.wired.com/story/google-location-tracking-turn-off/
(Private Browsing or Incognito mode may be useful to avoid Wired's "n free articles left" limits.)
Wired also links to the related AP article "Google tracks your movements, like it or not" (August 13, 2018).
Two of the photos from there:
"Kalyanaraman Shankari, right, and her husband Thomas Raffill hold their phones... Shankari, a graduate researcher at UC Berkeley who connects commuting patterns with urban planners, noticed that her Android phone prompted her to rate a shopping trip to Kohl’s. That happened even though she had turned off Google’s “location history” setting, which according to the company should prevent it from remembering where a user has been."
"...a mobile phone displays a user's travels in New York. Google records your movements even when you explicitly tell it not to. An Associated Press investigation shows that using Google services on Android devices and iPhones allows the search giant to record your whereabouts as you go about your day."