Jane Appleby answers questions from her students:

Q: What primary colours do you use?
A: I use light yellow, pink toned red, light blue, mixed with black and/or white.
I can mix all the colours with these but some pigments mix better than others and they vary in strength. Favourite Acrylic Paints: Hansa Yellow light, Quinacridone Magenta, Phthalo Blue (green shade); Ultra Marine Blue and cobalt blue are other favourites as is Cadmium Orange, Quinacridone gold and Umber for darks.
Q: How do you determine your painting is done?
A: The Three C’s
I look for the 3 C’s. These are Contrast, Colour and Composition within the painting and ask myself questions about the piece.
Contrast:
Do I have at least three value tones? Where is my main highlights and what are they presenting. Are the darks in strategic places to bring about the best contrast where it is important or do they appear like holes in the painting? The value contrast is the first major impact and if I squint does anything catch my eye that doesn’t seem right? If it seems to draw too much attention then I try to either to decrease the contrast or increase it elsewhere. Placing a white mat with a black sub mat helps to look at contrast.
Colour:
Did I use colours that are pleasing or setting a certain mood?. How do the colours flow and are there soft blended areas that help transition through the piece? Colour contrasts are effective visual components – did I place them where I want that impact. Do adjacent colours enhance each other or make reverberations. Do the same colour tones bring your eye through the entire painting and are they ment to or to keep you in a certain area longer (like in the focal point). Are warm colours bringing shapes forward and cool making them appear to recede? Do I have a small colour surprise as well as some areas of less intensity for rest. Have I used my whole palette including the three primaries that I decided to work with for that piece?
Compostion:
What did I intend to compose: a picture of something or impression of something within?
I sit with the painting in my living space where I walk by casually and notice things that may need change. For instance is the subject off centre for a more pleasing affect or if it is central what impact is it giving? Where are the contrasts and what are the harmonious components? What is the primary theme of shapes or repetitions that are presented and are they varied enough in size and shape and have colours that support the theme? Is there a linear, diagonal or circular Theme and a counter theme or point? Is there an area of impact that is interesting or entertaining visually with brush strokes, detail, interesting shapes or colour expression. Is my eye led through the whole painting and does it imply the subject to some degree while leaving something for the view to interpret? Do I get stuck anywhere? Where are the areas of high contrast vs. low contrast, warm colours vs. cool colours? Do any areas cause me to leave the painting and what brings me back into it?
It takes some time to ponder all of these elements and most of the time not all of them matter. This process becomes an intuitive thing that I mainly analyze to eliminate undue distractions in the piece. If it seems to work I leave it. Usually I resist changing too much in case I over do it. Most of the time the painting left in its initial expression with a few adjustments is what works best.