I'm new to AE so this question might seem very simple for you but if you help me to find the answer I will be very thankful. I wonder can we automate some actions applied to the different clips to the other group of clips? What I mean... For example we work with 3 different pieces of the videos plus one background picture. We process keying, re-scaling objects, make color corrections, etc. and then put all 3 objects together onto the background picture. I'm asking can I take 3 other different pieces (from other clip sources) and automatically apply the same actions to them? If it's possible it would help us to save much time... thank you in advance for your answers!
You can replace footage by selecting the new footage in the Timeline then select the new footage in the Project Panel and then hold down the Alt/Option key and drag the replacement footage to the timeline. This works as long as the footage is the same size and frame rate.
You can duplicate layers in the Timeline and then replace footage in that duplicate.
You can select all animated or modified properties in a layer by pressing the U key twice, then selecting everything in the layer that has been modified by dragging a selection around them, then go to Animation-Save Animation preset. You can then use that animation preset to apply exactly the same animations and effects to a new layer.