First, manage the dns with a third party dns service.This cannot be emphasized enough. Do not use your registrar's DNS. Do not use your registrar's hosting. Do not use your host's DNS.
The three elements -- domain registration, DNS, and web hosting -- should be segregated. That way, if you have problems with one, through chance, malice, or incompetence, you can exercise the other two items to work around the issue.
E.g.s:
If your web host is DDOSed, change the DNS entries to point to another host; minimizing downtime.
If your DNS servers are taken offline by legal action against the company that owns them, change the published servers at your registrar.
If your registrar goes bankrupt, your DNS and hosting will continue running smoothly while ICANN handles the domain management.
While you're at it, host your email somewhere different than your webhost. If you're account gets disabled because of a billing mistake, you want to get the email that tells you about it, right?
It's not even that expensive to implement these steps -- $25, maybe $50 per year. If you are at all serious about something on the Internet, spend the extra money!