Selecting USB for photo transfer always My question has to do with options when using the USB connector for Photo transfer. I have a LG K10 phone running Android version 7.0. 
After I select "Photo transfer" from the USB connector menu, I then select "Just Once" because I will at other time use it to charge my phone. What happens if I mistakenly hit "Always". How would I get back to using it to charge the phone?
You can easily switch modes if you mistakenly if you default to a selected mode. Just follow the steps below: 


From the Home screen, touch and hold the Recent Apps Key  (in the Touch Keys bar) > Settings > Storage > the Menu icon  (at the upper-right corner of the screen) > USB PC connection.


From here, you can choose which mode to use: 
 - Media sync (MTP)
 - Internet connection
 - Camera (PTP) to connect to the PC.

Tap Charge phone to use only the charging function and not the USB function. 

It also allows you to safely disconnect your phone from your PC.

Source: LG Support