It’s about rewarding desired behaviours and discouraging unwanted ones. This balance is developed through your relationship with your dog.
Are you strong and fair and worthy of following, or are you weak and can be safely ignored? Your dog does what you ask because it respects you, not because you bribe it with treats.
Ask yourself, does your dog respect you?
Respect is gained by being consistent in the messages you send your dog, this develops trust, your dog understands where it stands with you at any time.
So, it’s not hard to have a well-trained dog, build your relationship, be consistent, praise your dog when they get things right and correct where necessary, always remembering to end training on a happy note (eg: simple sit) and praise afterwards. ‘Good Dog!’