DNS TTL: By record vs SOA

I’m going to be changing a website from one of my dedicated IPs to my shared IP. I set the SOA properties to a very low TTL, but was about to make the change and noticed the A records for the site and mail. subdomain were still at the high default.

I’ve updated each record to a low TTL, should I now wait until the default timeout passes.

Does SOA override these individual records or should I wait until the default timeout passes again on the individual records before making the change?

From my Googling it seems that SOA is used first, then overrided if there is a TTL set for the individual records. So looks like I’ll wait another 12 hours before making the change.