When I'm retouching a series of images sometimes I like to keep the look and feel consistent throughout the images. As such, it's a waste of time for me to re-engineer every layer adjustment for each additional image.
Instead what I'll do is simply copy the existing layers from the original image and paste them onto the new image from the same set. Of course layer masks won't translate over but if the set is consistent with exposure and white balance, I'm saving myself a ton of work... particularly the trial-and-error time expense when I'm just trying to dial in the feeling of the set.
It's not particularly creative and I don't always simply paste old layer adjustments onto a new image (from the same set), but it does save me a ton of time (because time is measured in metric tons LOL).
How exactly do I do this? I put the two images side-by-side in Photoshop, select the first image, select all layers from that image and then simply drag them over to the new image.
That's it! Tons of time saved!