Cookies
Cookies can remember sessions, preferences and identifiers. Clearing them can remove some stored tracking data, although it does not erase every form of identification.
Fingerprinting
Websites can combine browser and device characteristics to create a fingerprint. Unusual configurations can sometimes make a browser more distinctive rather than less.
Extensions
Install only extensions you actually need. Every extension adds software that can potentially access browser data.
Browsers
Privacy-focused options include Firefox-based browsers such as LibreWolf and anonymity-focused software such as Tor Browser. Different browsers have different threat models.