If you own a MacBook that is of 128 GB or 256 GB storage then there is something you need to worry about as it gets packed really fast. If you edit a lot of videos, store lots of movies then you should get an external SSD that is on heavy discount right now on Amazon.
My Passport portable SSD from Western Digital is up to $336 Off depending on the storage you choose. Currently the available storage sizes are 256 GB, 512 GB1 1TB and 2TB. Check out all the discount price here:
WD 256GB My Passport SSD Portable Storage $100 $80
WD 512GB My Passport SSD Portable Storage $160 $100
WD 1TB My Passport SSD Portable Storage $340 $180
WD 2TB My Passport SSD Portable Storage $700 $364
From the Product Page:
Blazing-fast file transfers with reading speed up to 540 MB/s
Password protection with hardware encryption
USB Type-C and USB 3.1 Gen 2 ready; USB 3.0, USB 2.0 and USB-A compatible
WD Discovery software for WD Backup, WD Security, Social Media and Cloud Storage import, WD Drive Utilities
Trusted drive built with WD reliability.Pre-Format:exFAT