Flowers are also a great subject to draw! One of the best ways to help an artist improve and or understand shapes and structure, is to practice drawing flowers.
In nature there are basic shapes and these can be seen in flowers. From circles to triangles, they sit together to make the basic structure that the human see's before it. An artist sometimes has to get behind the beauty and see the basic shapes. In flowers this is a good approach. It is easy to be over awed by the colours and texture of the flower and so miss the basic shapes that are there in front of you.
So next time you look at flowers, after enjoying the beauty, try to see the basic shapes that go to make up what you see before you!