When one is awed by a seaside sunset, it is easy to overlook a basic rule in photography. Keep the horizon level. A tilted horizon is especially noticeable in pictures of the ocean. Unless it is intentional, make it a habit to level properly whenever the horizon is visible.
Even without a levelling gauge or grid lines, you can level by getting the horizon line parallel to the top or bottom edge of the viewfinder (or LCD).
Although an image editing software can rotate your image to correct framing error, it is better to get it correct in-camera. Each time you level with software, you lose part of the picture due to cropping
Make a conscious effort and after a while it will become a subconscious effort each time you pick up the camera to compose a picture.
Photographed at Bagan Lalang beach.
Olympus OM-D, ISO 200, f10, 1/320 sec.