I see this question has been sitting here for quite some time, now, but here is my answer:
I use a medium for glazing, and layering that I invented for my own use. It keeps my palette open for an entire day, yet it dries within a day or two, once the paint has been applied to canvas.
This is my recipe:
1 portion Linseed Oil
1 portion Walnut Oil
1 portion Venice Turpentine (the RESIN in this mixture)
2 portions Oil Of Spike Lavender (the SOLVENT in this mixture)