The most basic and important thing for a good relationship between parents and children is to understand the child's emotions.
In the three-step discipline formula, understanding your child's emotions and needs is the very first step.
When a child whines and throws a block because he or she is having trouble fitting the block together, rather than just saying, “You can’t throw the block,” if you read his or her feelings and say, “I see you were frustrated because the block wasn’t fitting together well,” the child will calm down and have time to listen to the rest of the story.
If you just give your child a restriction like, “Don’t throw the blocks,” without taking this step, their emotions will only get worse, and they won’t learn why their behavior is problematic, what negative consequences throwing can have, or how to express their anger.

--- From "Chapter 1: 'Discipline' If You Know It Properly, You Can Succeed: Improper Discipline is Counterproductive"

A baby who has just started walking will be curious and have fun with everything in the world.
Always give your child ample opportunities to explore his or her surroundings on his or her own.
One of the most important things in disciplining children before and after their first birthday is to distinguish between what they can and cannot do.
The child is learning to differentiate between these two concepts: 'I can walk on the path near my house without holding my mom's hand', and 'I have to hold my mom's hand in places with lots of cars and strangers.'
If you don't give your child enough opportunities to explore and restrict their behavior everywhere, not only will they have difficulty accepting the restrictions, but they will also have fewer opportunities to see and learn about the wider world.
--- From "Chapter 2 Seed Stage | Around the Ages (0-15 Months): A Child Who Won't Hold Your Hand on the Street"

One of the skills needed to help children at this stage when their autonomy is developing is to provide them with a 'little help' so that they can do things they want to do on their own.
At this time, you need the ability called ‘task analysis.’
Task analysis, well known in special education terms, is the process of breaking down a task into smaller substeps.
It's useful for children to learn and acquire new skills.
For example, even the act of a child putting on socks on his or her own can be broken down into smaller steps.
Put your foot into the sock, put your foot all the way into the heel, pull the sock up over your ankle, and align your toes with the end of the sock, like this.
If your child is good at putting their feet in socks but has trouble putting their heels in, you can help them a little.
This way, even if your child can't put on socks from start to finish, there will be a few steps they can do.
Then, from the child's perspective, by experiencing small achievements, they can develop motivation to "keep practicing and try to do more on my own" rather than "I want to give up because it's difficult."
--- From "Chapter 3 Sprout Stage | Around 2 Years Old (15-30 Months): A Child Who Gets Annoyed When You Do It When He Asks"

Parents should never be judges or bystanders when conflicts arise between siblings.
When parents become judges, they end up arguing over what the children did wrong, who did worse, and even punishing them.
If the parent says, “Oh, I don’t know! You two figure it out!” and becomes an bystander, the children’s conflict will either escalate or end in frustration.
An even worse situation is when the parent unilaterally forces one side to make concessions.
“He’s a baby.
“Sister, give in!”, “You’re the younger sibling, so you should listen to your brother!” In cases like these, the one who is forced to give in is left with only resentment and anger.
The most important thing is that neither child learns how to solve problems.
So, what should we do if conflict arises between siblings?
--- From "Chapter 4 Tree Stages | Around the Age of 30-48 Months: Children Who Conflict with Siblings"

Children's attention span at this age is not very long.
Therefore, you need to consider whether the message you are conveying to your child is too long and wordy.
When disciplining a child, it is best to use simple, clear messages. If the child keeps getting sidetracked and misbehaving, it is best to discipline the child in a quiet place without toys.
When dealing with a child who is playing around or doing other things during discipline, the important thing is for the caregiver to not get caught up in the child's behavior and to faithfully convey the disciplinary message that was originally intended to be conveyed.
Be careful not to lose sight of the original message you were trying to convey and get angry by saying things like, “Why are you joking while Mom is talking?” or “Look Mom straight in the eye!” This can obscure the essence of discipline.

--- From "Chapter 5 Fruit Stage | After 48 months (48 months): Children who play and do other things during discipline"