You don’t need to show a cat how to use a scratching post — they already know! Furthermore, holding your cat up to the scratching post and forcing her to drag her claws on it may actually frighten your kitty and teach her to avoid the scratching post completely.
You should, however, reward your cat for proper scratching etiquette with praise and a yummy treat to reinforce the good behavior. You can also encourage your cat to investigate the posts by scenting them with catnip or hanging toys at the tops of the posts. Take care to place posts in areas where the cat will be inclined to climb on them.
Finally, don’t throw away your cat’s favorite scratching post when it becomes unsightly. That’s when they’ve broken it in! Many cats prefer shredded and torn objects because they can really sink their claws into them and they’ve marked it as their own with the scent glands in their paws.