border for cutting

I often will drag images to a new canvas for printing.
I can do a small area crop to print so i can save both ink and paper.
Just start with a new file that is 8x10 and the same dpi as your images you want to print. Crop your photo and flatten the image. Drag the photo to the top corner of the page and do a print. Assess it and if changes need to be made just do two steps backwards to your original photo and make your changes. Crop and flatten once again and drag the photo onto your printing page so it sits beside your first test. You can now either just hide the first tests layer or drag it to the trash.
I find when i make my final print, if the background or any part of the photo is white and is touching the edge, i never know where to cut it because there is no seperation between the photo and the white paper.
Make a small border for a cutting guide.
- select - select all.
- select - modify - border and enter 1 pixel.
- edit - fill and fill with black.
- select - select all.
Then you can drag this file to the printing page and see where it ends.
I have an action made for this process so i just need to hit a button and it is all applied.