The easiest quickest way to solve lots of behaviour problems is to teach one easy skill really well, practice practice practice ( you can do this a few minutes here and there ) and reward it REALLY well - touch your hand , focus on you , come to you ,heel . When your dog is reacting at the window to a passerby , taking food off the counter , running away with an item , pulling on the lead , reacting to a dog , digging up the plants, chasing the cat , going nuts at the doorbell, jumping on people, laying on the furniture - whatever - you can ask the dog to do the skill you have taught . If your dog does what you ask , it stops doing what you dont want !
