There is a app that I have on my Android phone that allows me to backup certain folders to Google Drive and keep the folder structure intact which has many benefits.
The app that I use is called DriveSync
One of the benefits of using this versus using some sort of built in backup is that not only can this backup stuff from your phone / tablet, but you can also push stuff to your phone and or tablet with this.
By this, I mean that the application has a few different sync methods.

You can upload to Google Drive, you can download from Google Drive or you can 2 way sync. The 2 way sync will look at your device and then look at Google Drive and make sure that they both have the same files. Download any that need to be downloaded, delete the ones that should be deleted and then upload the ones that need to be uploaded.
If you do not have easy access to plug your phone into a computer to transfer files to your phone, you can upload them to your Google drive folder, then when you have the conditions correct to sync (The app lets you dictate when it will or will not sync, such as either connected to WiFi, plugged into a power source, etc.. ) then your files will be downloaded to your device.
I will use this to keep my media files (ringtones, notifications, downloads, etc.. ) in sync between my cellphone and my tablet. I also have it installed on my brothers cellphone so that we can share downloaded pictures and what not.

I did pay for this application, and I think it is worth the price.
Per the description of this app:
"Autosync Google Drive lets you automatically sync and share unlimited files and folders with Google Drive cloud storage and with your other devices. It is an ideal tool for photo sync, photo upload, music download, document and file backup, automatic file transfer, automatic file sharing between devices,... New files in your device are instantly uploaded to Google Drive. New files in Google Drive are automatically downloaded onto your device. If you delete a file on one side, it will be deleted on the other side. It works across multiple devices (your phone and your tablet). If their folders are synced with the same Google Drive account, they will be kept in sync with each other. This is how Google Drive desktop client works but it's not the same with the official Google Drive Android app. The Google Drive app is all manual. Autosync Google Drive is all about automation."