[nilmask]

You want multiple NS records containing hostnames of nameservers from two or more providers on independent infrastructure (i.e. not two providers that are both hosted on, for example, AWS' compute).

I would advise against running your own nameserver unless you have confidence in your ability to operate it correctly.

You can increase the TTLs if you don't anticipate record data changing frequently, or are able to tolerate delays in your DNS record changes being served (until the cached answers expire).

Choice of resolver (e.g. 1.1.1.1, 8.8.4.4) is out of your control (except of course, on your own devices and machines). Increasing the TTLs may improve robustness, assuming that your clients' resolvers are well-behaved and respect TTLs [0].

[0] https://www.ctrl.blog/entry/dns-client-ttl.html