It helps me and it may help you to consider your painting in progress, not as a whole but in terms of co-joined areas. I prefer to call them passages. These so-called passages in oil painting abstracts are important as individual units and when these units are reasonably intact then they can contribute to the whole more effectively. I am sure there are parallels in the other arts. I know music refers to passages of a piece of music which ends and flows into another part or passage of symphony.
Especially in large paintings it is easy to become a little lost. I have found that going back and working carefully on getting one section properly in balance then it allows progress to another section. It is better to do this than to have an entire painting which is only partially rendered. I will often develop these passages somewhat at the same time – that is dabble with one and then dabble with another to bring them along at roughly the same pace. In this way the painting begins to take shape and the whole begins to be recognized.
It is important to study a painting and determine strong or weak areas (passages). Inevitably you will find some passages as you go along are quite fine and are standing on their own and they have even successfully integrated with the rest of the painting. When all the components are integrated then the painting is of course, nearing completion. By thinking in terms of passages or sections you can visually breakdown a painting and concentrate on getting that one section correct or at least develop it further to bring it up to the level of the rest of the painting.