For any major release of WordPress / Theme / Plugin, I will always wait for at least minor update is release.
Example like WordPress 5.5, I’ll wait for the release of WordPress 5.5.1 or WordPress 5.5.2.
To be safe, I always wait for another 2 weeks for after the major’s minor release to be safe. For your information, I waited more than 3 months to update the major release of WordPress 5.0, which is WordPress 5.0.4.
As for minor release on security patch, I’ll configure auto update with this code snippet in wp-config.php.
define( 'WP_AUTO_UPDATE_CORE', minor );
How I Update WordPress site
I always get all my client daily backup to 3rd storage. And I never depends on hosting service provider backup. Reason is with own backup, you can restore any time you need without going to any 3rd party for help. You can easily restore the site in a minute.
2. Create a staging
With the backup, you can easily create a staging site for you to test the update.
You may learn how to create staging site
3. WordPress / Theme / Plugin Update
Update the WordPress version and scan through the website frontend and backend to see any possible error.
Enable WP Debug in wp-config.php to double check any possible error.
define( 'WP_DEBUG', true );
Debug any warning or error display on the website.
Once everything is solved, change the true to false
define( 'WP_DEBUG', false );
4. Push to live
Once push to live, remember to have another round of cross-check.