Select an object.
Click and
then a second object to create a new object from the union of the two objects.
Click and then a second object to create a new object
from the intersection of the two objects.
Click and then a second object to subtract the first
from the second.
It is also useful to optimize objects prior to boolean set operations if an object has been deformed, point edited or face edited. This will result in faster and more accurate results.