A tired dog is a happy dog and usually stays out of trouble. When we first started leaving Loki outside of his crate while we were gone he would chew something to pieces...shoes, pillows, hats, a DVD case, Cards Against Humanity????? and anything else he decided might be tasty. To fix this we started giving him something to do while we were gone. We use several different toys/bones but the easiest thing to start with is a Kong Wobbler.
Here are a few other treat/food dispensing toys with good user reviews.
If it's not meal time, sometimes we'll give him a little food but we usually give him peanut butter in a dog bone or in the Kong Extreme. We use the extreme version since he is a very strong chewer. It's comes in handy if you have wood floors because it will bounce instead of denting them,
These things worked about 99% of the time, after a couple months. The goal is to get your dog to associate their owner leaving the house with something positive. It will take their mind off the fact that you left. Since Loki is a weimaraner his separation anxiety is through the roof. Every now and then we'll come home to something small chewed up. But his behavior is light years ahead of where it used to be.