About landscape painting. In my opinion this needs the most thinking about composition. There are some basics one should consider, first to have a center of interest (coi), a point of special interest in your painting. This could be either a person or animal or special tree, house, a spot of light, etc. When you consider your sheet or board as divided into three sections horizontally and vertically you get four crossing points. Each of these crossing points is a good choice for locating a point of interest. You can also create a path into/in your painting for the eyes of the observer. You can guide the eyes, by lines, contrasts etc. along this path into/in your painting (and normally to the coi). Good is also to know first what your painting shall be about and to emphasize this.
There are lots of books about composition and it can get really complex, but for the beginning it is best to concentrate onto some basic rules or it can get overwhelming. And it is also good to try several composition ideas is small value sketches (black, grey white) to see if your idea works.
