Correct operation of the shift paddles on the steering wheel ?

Hello together, would like to know, since I get the x-perience delivered with shift-buttons, how to use them properly. In manual shift mode, the shift-buttons are used, the foot still hangs on the accelerator pedal, or you should just before you use the shift-buttons, so switch up or down, take the foot from the accelerator pedal and give it back gas after switching. Meaningful, I think the shift-buttons are mainly in manual mode, at mountain descents in the mountains, to pass through Ru I think that if you have switched from D to 2 when you are driving down the mountain, I don’t think there are these switch steps in automatic mode, D, 2 and 1 !? I think you can use the switch buttons to keep the gears low. Greetings, OliOla