You must get yourself a bottle of Liquin from Winsor & Newton. This yucky brown goo, when mixed with your oils, helps to make them very transparent and they dry incredibly quick. I have done as many as 3 layers of glazes in 1 day using this wonderful stuff. Do a layer 1st thing in the morning, set it out in the sun, another layer after lunch, back in the sun and another at night.
I like to have 3-5 paintings going at once. It always gives me something to do. Right now I only have 2 going on and Im getting a bit antsy