These are some really important lessons regarding search/browser histories.
Rule #1: Don't delete your whole history, that just causes suspicion.
Rule #2: Don't forget that smartphone keyboards save inputs including websites. Those need to be deleted separately.
Rule #3: Don't ever leave any suspicious websites open when you allow someone else onto your device.
Rule #4: Not about search histories, but make sure you know what kind of photos/documents/videos are saved on your device. Try to hide those important ones real good.
Rule #5: Don't assume incognito mode can protect you from being detected, since that's not what it does. Use a Vpn instead for not so legal stuff.
Rule #6: A Vpn won't protect you from suspicion if you're using torrents. Your internet provider will see you uploading a massive amount of files and might send you a warning/heads up. Just don't use torrents since those are actually illegal. Whilst downloading that file, you are simultaneously uploading it for other users to download. And that is super illegal and will cost you alot of money (if you are caught).