I don't really think this one looks that much like a watercolor... parts of it do, a low opacity setting and not much blending is one of the things that causes a watercolor effect. If you want an oil painting look, use a heavier opacity, a little larger brush and let your strokes show towards the end of your drawing. (Don't blend stuff too much at the end or it will look blurry) Hope that helps... This is pretty.. I like the way you composed it where the hall leads to the window view.

hey! I never said you could draw me naked! geez, ya added my gray hair and all.... no fair!
hehe nice draw!