There are two components to an abstract painting that I believe are the most important. Understanding these two will take you a long way to appreciating a painting and perhaps they will help you decide whether to purchase it or not and have confidence in your decision. The first is color. In a painting devoid of easily recognizable subject matter (or a subject all together) color is the most emotional element. It is the one you are most likely to respond strongly to. On the practical side you may just be looking for a painting that goes with the color scheme of your living room, but if you're open to it you can gain a more sophisticated knowledge of color. Artists have at their disposal several systems of color theory and they choose which to use based on what they want to communicate. A few very basic types of color compositions include, analogous where all the colors are related and harmonious. This grouping of colors produces a very unified, cohesive painting. Some will find this cohesiveness very pleasing to the eye, producing a sense of tranquility, where everything fits together and belongs. So when you look at abstract art notice the colors and decide whether they are harmonious and if you like that effect. Another very common color construct is the complementary color scheme which makes use of opposites, red/green, blue/orange, yellow/purple. These combinations produce a lot of visual vibrations in the eye and convey tension, excitement, contrast. Some will like this visual excitement for its power and variety. If you can place the painting in one of these two broad groups and note your reaction you'll begin to discovery and understand at least one element in an abstract painting that you are drawn to or you dislike.