Here's a really easy video about how to back your photos on the phone itself
To restore just open the app after the reset and the photos will come back

As far as I know, a special designed android data backup app could transfer everything from your phone to computer in few steps, and you don't need to root your phone, just need enable usb debugging on your phone.

will this restore the short cuts saved to home screen? wIll it rebuild the other home screens and widgets?

Thanks for sharing.

You can also use Jihosoft Android Manager to do the Samsung Galaxy S6 backup and restore.

Back Up Applications:

1. Tap "Apps" on the home screen
2. Tap "Settings" and scroll to "Personal"
3. Tap "Backup & reset"
4. Tick the boxes associated with "Back up my data" and "Automatic restore"

NOTE: App data will be restored automatically the next time you sigh in with the Google account used for the initial backup

Back Up Contacts:

1. Tap "Apps" on the home screen
2. Go to "Settings" and tap "Accounts"
3. Select the account you wish to sync your contacts to
4. Tap "More" > "Sync now"

NOTE: Your contacts will be restored the next time you sign in to the Google account used for syncing the contacts

Back Up Media Files on a Windows PC:

1. Connect the Samsung Galaxy S6 Active to your PC via USB
2. If necessary, swipe the "Status" bar down and tap "Connected as a media device" > "Media device (MTP)"
3. In the AutoPlay window click "Open device to view files"
4. Navigate to the desired files on your phone
5. Copy the files, and transfer them in the desired location on your PC's HDD

To restore media files from a Windows PC:

1. Connect the SGS6 Active to the PC (ensure "Media device" is enabled)
2. Navigate to the phone's storage
3. Open a second Windows Explorer window and locate the backed up files on your PC
4. Transfer the files on your phone storage
5. Once the transfer is done, click the "Mass storage device" icon in the system tray, eject the phone storage, and safely disconnect it from the PC

Back Up Media Files on a Mac:

NOTE: Skip the first 3 steps if Samsung Kies is already installed on your Mac

1. Open the Internet explorer on your Mac and navigate to Kies
2. Click "Download for Mac OS"
3. Follow any on-screen prompts to download and install Kies
4. Connect the SGS6 Active to your Mac via USB
5. If necessary, swipe the "Status" bar down, tap "Connected as a media device" > "Media device"
6. Launch Kies on the Mac
7. Click the "Back up / restore" tab
8. Click the "Backup" tab
9. Select the check box associated with "Music" and / or "Photos". Otherwise click "Select all items" to back up all of your files
10. Click "Backup"
11. Once the process is done, eject the phone's storage and safely disconnect the phone from the Mac

To restore media files from the Mac:

1. Follow steps 1-through-7 above
2. Click the "Restore" tab
3. Click the check boxes associated with "Music" and "Photo". To restore all of your files, click "Select all items"
4. Click "Restore" and follow any additional prompts if necessary
5. Once the files are restored, eject the storage and safely disconnect the phone from the Mac