Step 1: Open image
Step 2: Scale image to proper resolution
Step 3: Import layer
Step 4 (optional): Reduce resolution



Step 1: Open image
Step 2: Scale image to proper resolution
Step 3: Import layer
Step 4 (optional): Reduce resolution



Once you have a layer done, it only takes few minutes to place it on any photo.
So you should spend more time on the original, since it is so easy to duplicate.