When starting a painting, the biggest things that help me more than anything are making 2 studies: a noton and color study. This not only helps to make a strong foundation, but ironically also saves time since most of the problems are being solved before the painting even gets started. I do my studies each on an 8”x 10” canvace with acrylic paint on the notan, and oil on the color study.
Notans
Notans are incredible tools to help figure out the light and dark designs of a painting. They help figure out the design and composition of your picture on a smaller image before you get stuck on your actual painting. Most of the time, if a painting isn't coming together, the light and dark design isn't very interesting. If you can make a notan design you are happy with, you will almost certainly be happy with your paintings. They always say that values do all the work, and color gets all the credit.
To make a notan, I always use acrylic on an 8”x 10” canvas. The values of your picture that are lighter will be pure white, and the values that are darker will be pure black. If you are painting from life, the easiest way to tell what is in the light and what is in the dark is to close your left eye and squint hard with your right.
Remember, notans work great for realistic and abstract painting. In fact, some abstract artists use the idea of notans as their finished paintings (look at Franz Kline and Robert Motherwell).
Color Study
Once the notan is figured out, I use a separate 8”x 10” canvas to figure out the color design. Whether my colors are based on reality or made up, this is a great way to figure out the color design of the painting. The main thing I try to remember at this stage is that the values of the colors need to match the values of the notan design.
Bottom line, this HELPS the painting be more free and spontaneous
For anyone worried about losing the spontaneity of their painting by doing these studies, I strongly urge you to try it and see for yourself. One thing these studies have done in my own work is prevent me from overworking my painting as most of the problem solving is done way before the actual painting has even started.