External Backup for multiple iOS devices

HELP! I have a lot of devices and my backups are taking over my work computer... you understand, I need to work to buy all these devices. I am a computer consultant and have a lot of large files on my laptop.... LOL

What I want to do is backup my iOS devices to an external drive - no I don't want to drag the backups to an external drive, I have no room and it is an inefficient use of my time.

I have the largest hard drive available for my MBP, so that is not a solution.

These are the iOS Devices I am backing up:

* iPhone 6s 128Gb paired to an Apple Watch

* iPad Pro 128Gb

* iPad 64Gb

Anyone have any ideas for a direct back up from iTunes (on my computer, I don't want the entire library on an external drive) to an external drive.

Thank you!

Pam

PS I would prefer not using Terminal - last time someone gave the text there was a syntax error that erased important files!