Everything can be viewed as made of identifiable shapes. When thinking about drawing and object that is made of many different shapes, like an animal, lightly draw all the shapes in the positions you see them on the animal. This will help you lay out the area where your animal will be drawn.
Easy Animals to Draw A webiste with a wide variety of animals to choose from
The negative space is the area around the objects.
When objects overlap it helpful to draw the shape completely, then go back and erase the part of the line that is not showing.
It’s very difficult to calculate how far a person’s head is from the bottom of his or her feet, the distance from one ear to the other, or the distance from a far tree to one in the foreground unless you draw all the shapes in between.
Layering values helps cover up early mistakes when laying out the drawing. When starting lighter you can make adjustments without ruining your paper by over erasing.
The Book Of Mistakes by Corina Luyken
Mess up Fix up! Everyone makes mistakes when creating art. This book and it's fabulous illustrations gives great examples of how to work through your drawing mistakes!