Take a look at this schematic especially on the usb otg part of it.
It uses a SY6280 "5.5V, 2A Low Loss Power Distribution Switch" As a means to control the 5V usb-bus power.
I was wondering if it would be a good idea to implement this short of thing on all my peripherals in order to enable them or disable them according to my power requirements e.g sd card,sensors, relays etc .
My design features a 18650 battery to power the device when ac mains is out ,like a ups, would you consider this approach effective as a means of power management during lost ac mains in order to power only the necessary blocks of my design.
Looking forward to your reply George