This question can take on a number of perspectives and implementations.
I've implemented DNS over TLS on my router:
https://openwrt.org/docs/guide-user/services/dns/stubby
https://github.com/openwrt/packages/...iles/README.md
With this, every device needing DNS resolution on my LAN references the DNS "stub" on my router.
Cloudflare can also check your DNS implementation at this URL:
https://1.1.1.1/help
Lists of Alternative DNS servers:
https://www.lifewire.com/free-and-pu...ervers-2626062
Free, Open DNS servers tend to be less resiliant:
https://www.opennic.org/
My portable device, running GrapheneOS, defaults to Cloudflare's DNS over TLS.