USB C Flash Drive
It's a good idea to switch to a USB C flash drive that you can plug directly into your MacBook Pro, but it's also smart to get one that includes a normal USB plug as well. With this setup, you can plug it into any computer you need, including your other computers or a client computer.
The top option is from SanDisk. You can get a 128GB USB C flash drive with normal USB connection also built-in for $46.36 or you can go for a smaller option and get 32GB for $16.95 and 64GB for $24.99.