Use the Rule of the Third Correctly
Before you do anything else, try to turn on your TV and find a news channel. Wait until you see the newsreader. Where is he sitting? In the middle of the picture? No, he is sitting either in the left or the right third. And that is the Rule of the Third.Long before the photography painters found out, that if the main subject was placed either one third or two third from the top and/or from the left, the painting would look more balanced.
Actually one third is not the absolutely correct place to place the main subject. There is a very complex mathematically rule that describes the Golden Section. But as long as you are not showing your pictures to mathematicians, it is just fine to use one third as a rule.
So learn from the painters and place your subject in the third parts of the photography. It can be either vertically or horizontal; or both.
The Rule of the Third is especially important, when you are photographing the horizon. A classic mistake is to place it in the middle of the photo. But as you have learned, it will divide the photo in two parts. The result is an unbalanced photo.
Instead look at the frame. What is most interesting; the sky or the ground? If there are beautiful clouds in the sky, then this part should fill up two thirds of the picture. Are the subjects on the ground more interesting they should fill up the largest part.
On some cameras the subject has to be in the middle to make it sharp. In this case you shall just place the subject in the middle of the frame, press the releaser half down and then turn the camera so it points to the subject. Then press the releaser completely down.
It is okay to break the Rule of the Thirds (like all other photographic rules). But you shall know why you are doing it and therefore only do it on purpose.