Crop the image for printing and a better composition.
Open your image in Photoshop and go to the history palette, click on the camera at the bottom of the palette. This will make a snapshot 1, which is a record of the current settings.
Select the CROP TOOL from the tools palette.
In the options bar at the top enter 11.693” (29.7cm) width and 8.268” (21cm) height, resolution 300 px per inch. This will give an A4 size picture for printing on an inkjet printer. You can change these settings to suit your needs as required.
Decide which part of the area in the photo you want to retain. Click and hold the left mouse button and drag across the area you want. Because the dimensions have been entered for width and height, no matter what size you draw the selection it will remain in proportion for an A4 size print.
The corner handles can adjust the size of the area by clicking and dragging on one of them, dragging in or out as required. The area of the selection can be moved around by clicking inside the selection and dragging to a better position.
Bring the mouse outside the selection and it becomes a rotation tool. Click and drag, rotating to a new position. The cross hair target in the centre of the selection is the centre of rotation. Move it by clicking on it and drag it to a new position, say to the bottom left corner. Now go outside the selection and rotate to a new angle. This can give a more dynamic composition or it can be used for straightening a horizon.
Now press enter and you are ready to print your dynamic photo with a straight horizon in A4 size.
But if you are not sure about the results, go to the history palette and click on the camera at the bottom of the palette to make number 2 snapshot. The number 2 snapshot will be highlighted. Now click on the number 1 snapshot and back again to number 2. This way you can compare the different selections.
Saving your image without flattening under a new name will mean you can re-edit at a later date and still retain the original image