If I am without deadline pressure I really enjoy mixing colour in a systematic manner but I also enjoy just going for it. When time is of the essence this is a useful method. Here is how it works. I pile up all the colours that I think that I think might work, then I take a thin slice out of the middle. I mix that little slice thoroughly. It doesn’t take long if you take a small enough sample. If the colour is what I want, I go ahead and mix the whole batch. If it is not what I wanted I can add one or more colour and cut and mix a new sample. If I and way out I can always take the stack apart. ( I think that this is easier done with Fimo which doesn’t stick together until you add pressure.) When I have a stack that comes out to the colour I wanted I can take a picture of the stack and file it with the mixed colour sample. No exacting but it gives me the colour that I want quickly and a starting place for more exacting mixing.