Drawing eyes in profile and three quarter view is different from drawing them head on. At these angles, certain things like the waterlines, and the setting of the eye in the socket will be emphasized. The eyes may even appear to be different shapes.
In summary, start with a sideways "V", pay attention to how the waterline curves and follow it, keeping in mind that it may be more visible at certain angles. In quarter view, the setting of the eye in the socket is more visible, and the eye is usually more curved on top and flatter on the bottom.
A while ago I took a class in portrait drawing in which I picked up some tips that I think make drawing accurately proportioned faces fast and easy. They involve drawing basic shapes and then refining them and using lines to show where particular features will go. In the video below, I walk you through the process of drawing both a face looking straight on and one with a tilt, so you can see that even a slanted head doesn't have to be intimidating to draw.
Painter of portraits and wildlife