I've got the color but how do I approach form?

It's clear that in any successful painting the two elements, form and color, happily entertwine. It can be seen in a completely representational work and to the same extent in an abstract piece. However, it becomes much harder to analyze and accomplish a successful combination in a painting that is void of any representational references. There are of course multiple schools of abstract painting, from geometrical or minimalist abstraction to expressionist, to color field. Automated references drawn from imagination were employed by the surrealists. I, however, believe I'm not able to part with the connection to nature and its forms. Nor do I really want to as it truly provides the most varied choices and organic combinations. My idols like Kandinsky and 20th century Monet, for instance, successfully bridged abstraction and figuration by drawing inspiration from landscapes. However, the tricky part is determining which key elements in a painting get to stay when it's reduced to an abstract piece, and which are less important to the overall composition and feel.