One good way to do them is to make a good eye first. This sets in a good underlying structure for you to more easily make the rest around. The Iris size on the eyeball, varies much less from person to person. you get the Iris size right and you will know the size of the ball. I can find the ruff proportions of that if you like.

That will help you structure your lid and socket well around it. With the eyelid just make sure you leave a fold crease for the top lid. It is a good idea to put a tear duct in while your at it. Its often overlooked.