borders, like quilting can make or break the quilt-
their importance is certainly project dependant- some quilts need a border- some do not- some need lots of quilting- some do not- it all depends on the quilt-
sometimes people add borders just to add size to their quilt- a border should get as much (if not more) careful thought as the quilt body received- they can be very important---or they can cause you to loose the quilt.
it's all a learning process- learning to size your borders to not overwhelm the body- the learning to use multiple borders- or to determine when a border is appropriate or not- we all have to learn.