With the holiday season going full speed ahead, there's one thing you should do right away.
Backup your theme.
With the amount of chaos right now, I'm seeing many Shopify stores with coding mistakes and errors. Due to rushed work, lack of testing, or any of the other numerous reasons it's easy for your theme to get messed up.
If it gets messed up during your busy season, how much revenue would you be losing?
Downloading a theme backup from Shopify takes about two minutes. Yet it can save you hours of work and lost revenue if you ever need to restore it or pull code from it.
And don't trust just making a duplicate inside of Shopify. That's great for making upcoming changes to a theme but not for backups.
Download your theme file from Shopify (Themes menu -> Actions -> Download).
Put it someplace safe.
And sleep easier tonight.