Say "No" firmly or make a loud shushing sound immediately when catching them in the act of an unwanted behavior to startle them into stopping.
Verbal
Redirect attention from inappropriate scratching/biting onto appropriate toys to expend energy constructively instead through play.
Distract
Use feline deterrent spray, aluminum foil, sticky tape or upside-down vinyl carpet runners to make surfaces unappealing to scratch or chew on.
Deterrents
Generously praise and treat alternative desirable behaviors, like using scratch posts, to reinforce these good habits rather than scolding what’s unwanted.
Reward
Initiate playtime before typical times mischief occurs to release pent-up energy positively preventing bad conduct stemming from boredom.
Schedule
Understand occasional inappropriate behavior is inevitable for inquisitive cats. The goal is simply reducing, not eliminating completely.
Reasonable
Permanent change develops over consistent weeks/months. Refrain from yelling, hitting or rubbing nose in mess which frightens cats.
Patience