For a looser and flowing look and feel to my oil paintings, I've been experimenting with mixing cold wax with my oil paint. It seems to increase drying time, which is good in some cases, and to make the paint easier to move around with the odorless turpentine. It's also just a lot of fun to work with! Here are two of my latest paintings using the cold wax - Tangents - the large 36 inch square tree painting and Windfall - the 24 inch by 40 inch painting of a river with fallen trees. Both are on cradled birch wood panels. which is a great support for the wax medium. 

All of the paintings below are created with oil paint, though I sometimes use acrylic paint as a foundation underneath. I sometimes start with gesso then do a base painting in black and white and gray with acrylic paint and layer oil paint on over that, which is perfectly okay! As long as you lay your water soluble paints down first and oil on top you will have a stable painting.