The last few days, I have been copying layers and I found the current workflow quite slow. First, you have to copy the layer. Second, you have to scroll to the top of the target data frame, right-click on it, and select Paste. Finally, you have to drag the copied layer to where you want it. The scrolling up is a little slow, but the dragging down is very slow if you have a lot of layers.
My idea is that after you copy a layer, you would right-click on another layer and there would be an option to Insert Copied Layer. This would imitate Excel. Another alternative would be to have two options, namely Paste Above and Paste Below. The UX experts can figure the details out. My idea is largely just to be able to go to where you want to paste the layer and paste it right there. This is especially relevant when you just want to copy and paste a layer right above or below itself.