More often than not you'll need the skyline in a photo to be level. This is particularly valid in case you're shooting seascapes, generally the water will have all the earmarks of being coming up short on the casing.
Your camera's Live View screen has a lattice overlay that can be initiated in the menu to guarantee skylines are level, and it might likewise have an electronic level show that can be superimposed over the picture.
In the event that your camera does not have these highlights, utilize the columns of self-adjust focuses you can find in the viewfinder as an unpleasant manual for keeping the skyline straight.