Earlier quoted context omitted.
Well, you're already in the midst of downtime, so you have a head start. Aside from that, focus on two concepts: TTL and overlap. 1) On your old host, lower the TTL of all your records to something quite low, like 30 seconds. This will increase the burden on your nameservers, since records will only be cached that long, but it will make you more nimble as you make substantial changes. 2) Migrate your records over to…
Altering TTL won't do anything for you unless you do it before you start to make changes and far enough in advance that the current TTL will expire and servers will pick up the new TTL. Then when you alter DNS records the alterations should propagate much faster. If you're literally just changing DNS providers why would there be any down time - the record showing the IP where to find your website just gets grabbed fr…
Exactly.