How to organize the shutdown of peripherals during arduino sleep?

Question

Arduino

a screen, a sd card, a multiplexer are connected to the arduino, and through it,
I think, at the time the arduino falls asleep (it will be necessary to do this), turn off the power to
this periphery. So far, the thoughts are to use the controller leg and the transistor and, if necessary,
supply power to everything at once.
interested in outside opinion

Answer 1

Everything is as you described, just don’t cut off what Dunya will wake up for: the start button, power button, or which sensor

Answer 2

and here's another question to catch up
on the map and the "chip select" screen if there is no signal on it, the consumption is on or not

Answer 3

You can use the power management registers of the microcontroller peripherals.
You can read more in Saving Arduino Power Consumption .