Your pictures will be much better if you take them straight on, rather than at an angle. Do whatever it takes to put the item on a wall and stand in front of it. Photographing it from a tabletop or the floor makes the sides of your quilt angle in toward the top. Take your picture with good natural light, but not direct sunlight. The new fluorescent bulbs come in natural daylight and will give you clean light for your photographs, rather than the yellow light provided by old incandescent bulbs.
Some graphics software allows you to correct your pictures if they are not straight. However, it is not perfect, as shown below.
Place your quilt on a wall, rather than having someone hold it. Your quilt will not sag or have little fingers and feet attached to it.
If you do not have a wall, you can pin your quilt to curtains. You must do this at night when no light is coming through the curtains and you must pin the top in the center as well as on the ends. The picture below shows what happens when you pin only the ends and there is light coming in the window.