Abbey is 8 months, we've had pretty good luck from keeping her from chewing things by giving her lots of exercise and plenty of "approved" things to chew on like bully sticks. If we catch her chewing something she shouldn't we give her something she can chew on and it usually diverts her attention. We also bought a bitter apple spray (which you can get at any pet store) to put on things we know she likes to chew on. It works pretty well for her, although we need to reapply it frequently, but I have heard that some dogs actually like the way it tastes. It is worth a try though if you have a furniture item or something that she is drawn to.
I have to say though that the biggest thing that keeps her from getting into trouble whether that be chewing, or something else, is the exercise. We have a group of dogs we meet up with at a local dog park almost every day & we take her on plenty of walks.