A couple of years ago, I renewed the three domains I care most about (a three-letter one, my name, and a domain I've had since they were free from hostmaster) for as long as their respective gTLD registries would permit. I figure that plus a script I have that checks them for shenanigans[0] should keep them in good order.

0 - Checks every 30 minutes for changed nameservers, domain contacts, and if the renewal date is less than six months in the future. Texts me immediately if it there's a difference or once a week if no changes noted (so I know the script ran).