The easiest way to start a drawing is to start with simple shapes. Use quick and long lines to get going. Pretend you are trying to sweep something off your paper... only using your pencil tip. Try not to draw too hard since you normally need to erase these lines.
The head is like an upside down egg shape. Make sure you draw the whole egg and not just where the face is. I even drew the top of her head which doesn't even show in the photo. Draw a long line where the eyes would go (The center of the egg. The same distance from the top and bottom. Measure with your finger or pencil if necessary... don't be embarassed)
If it doesn't look like much to you, draw some more lines. Even "imaginary" lines like the center of the face or from Maki's right cheek to her shoulder. It will help you lay things out correctly.