Using Layers in your project
Layers make it easier to work with very complex drawings. They allow you to separate elements of your work and change things you want to change without affecting other parts of your drawing.
Macromedia FreeHand MXa:
If the layers panel is not already open, press F2 to open it. All FreeHand documents contain a Foreground, Guides, and Background layer. You have the ability to add more layers to your document by clicking on the arrow in the upper right hand corner of the layers window and clicking New.
To add an object to a layer, click on the name of the layer you wish to modify and draw.
You may hide layers that you're not working with by clicking on the check mark to the left of the layer. The images in that layer will disappear. To bring them back, click on the place where the checkmark should be.
You may also lock layers so that they cannot be edited. Do this by clicking on the lock to the left of the name of the layer you wish to lock. Now you will be unable to make any accidental changes to that layer.