Using a grid to draw something can be a touchy subject for some people.Some view it as cheating, other see it as a tool. I am in the using it as a tool group.
When I really can't get something right, I use a grid to help. After trying about a dozen times, I couldn't get the angle of the parrots beak right, so decided to grid the photo. Breaking large areas down to smaller ones, does help a lot when I just can't seem to draw that day :p