The strong composition in a painting is a characteristic that is not measurable or quantifiable and is based on different elements and the relationships between them. If the composition in the painting is done well you do not notice it initially; you know that painting has something particularly appealing. But when the composition of a painting is poorly made (such as when the subject floats in the middle of the canvas or tightly in a corner), the effect is very noticeable, and the painting feels uncomfortable.

If we were painting from the real world, we were isolating our subject and the key elements in a scene, checking their placement and determining the format. When there's a landscape outside, move around. Do not be satisfied with the first beautiful scene. The scene can change dramatically when you move your position by just a few meters. Move around until you find the composition that seems right for you.

Where is the focal point?

The focal point is the thing that is the main subject of painting. The focal point should draw the viewer's gaze towards him. It doesn't have to be an open "path", like a road that leads to a house; may be more subtle, a default line, such as a repeated color in flowers.

Are the values varied? Is there contrast?

For example, two-thirds in shadows, a third in light tones, and a small area or an object that has a medium tone. Often, the focal point is the area where there is the highest contrast of value. 

You may also consider for a balance and harmony of light and dark in a composition.

How many elements are there?

They have an odd number of elements in the painting rather than they seem. 

How are items spaced out?

Finding orderly and orderly arrangements of elements in nature is rare. Just think of the difference between a natural forest, where trees grow in every way, and a plantation, in which trees are planted in evenly spaced rows. Varying the space between the elements in your composition, the angles in which they are located and their dimensions make a painting more interesting.

Do hot or cold colors dominate?

It doesn't matter if the overall feeling of color in a painting is warm or cold, it just shouldn't try to be both.

Is There Unity?

Do the elements in the composition of the painting feel that they belong together or are they separate fragments that happen to be in the same painting? Sometimes, simplifying a painting and creating a more negative space can help create the unit.