I believe the most valuable skill one can develop is the art of asking questions.
It's a simple act, yet it opens doors to meeting fascinating people, having enriching conversations, getting helpful insights, and developing lasting friendships.
Questions, in essence, build the foundation for meaningful connections.

While asking questions is my favorite piece of advice, my best advice requires a bit more context.

To understand my best advice, let's start with my second-best advice which is the book called The 5 Love Languages.
This book illuminates the five fundamental ways people express and receive love. 

A common relationship challenge arises when individuals speak different “love languages.”
Imagine someone speaking only Chinese trying to communicate with someone who only understands Spanish. 

Both people may be passionately expressing "I love you!"
but their inability to understand each other is detrimental to the relationship.

While The 5 Love Languages offers profound insights, my absolute best advice is a book called Love and Logic. 

In contrast to the love languages, Love and Logic provides practical strategies for navigating what I call the "7 languages of anger"
and effectively teaches how to replace anger with cooperation.

This book transformed my life. 

A particularly impactful example occurred during an argument with my wife. 

In the argument, I found myself saying hurtful things. 

After I said them, Love and Logic helped me realize, 

"Why am I saying this to the person I love most? I wouldn't want her to speak to me this way." 

So I started applying the techniques from Love and Logic to myself
and I effectively shifted out of those anger-driven responses. 

This significantly improved our family life.

After studying these two books, I noticed one key difference between the anger and love languages is that anger is universally understood. 

Everyone speaks every anger language, often in combination, when upset. 

I've observed my children navigate these languages during disagreements. 

For instance, my son might start with a "lecture" anger language, 

and my daughter responds with "distractions". 

He might then combine "intimidation" with "avoidance" (like running away and slamming doors), 

while she counters with a mix of "threats", "manipulation", and "physical" anger—essentially using all the anger languages at once. 

Then I can simply use some Love and Logic techniques to de-escalate the situation and guide them toward cooperation.

Therefore, my best advice can be summarized as this:
If you can master the love languages and get control over the anger languages,
then you'll have conquered the most important and hardest parts of life.

I sincerely hope this advice benefits you as much as it has benefited me, as it has profoundly impacted my life.

It's important for me to note that Love and Logic doesn't explicitly label the "anger languages," 

and everyone gleans different insights from the book. 

Some focus on control, others on choices, consequences, or consistency. 

Some simply use the book's one-liners. 

I personally identified the anger languages through the detailed examples provided. 

You might discover something different. 

Although Love and Logic primarily focuses on parenting, its strategies are applicable to any situation involving anger management.

My short answer:
My favorite advice is to ask questions
because you can meet some great people,
have some great conversations,
learn a lot, and you could possibly make a new friend.
Questions can be the foundation of a lifetime friendship.

My  long answer:
My best advice is clearer if I start with the 2nd best advice I've ever received.

The 2nd best advice I have ever received is a book called The 5 Love Languages.
(If you can think of a 6th language, then you should write a book called The 6 Love Languages and you'll make a lot of money. )
This advice really helped me because it talks about the 5 ways people can express love.
To quickly summarize a really good book:
One of the biggest problems that happens in relationships is one person speaks one love language
while the other person speaks a different love language.
So it is like a Chinese person screaming at a Mexican.
They are both screaming, "I love you! What is wrong with you? Why don't you feel loved?!?!"
But they are screaming in different languages and don't understand each other.

While this advice is amazingly helpful,
the best advice I've ever received is a book called Love and Logic.
Where The 5 Love Languages talks about the 5 ways to give and receive love...
Love and Logic teaches you tips and tricks to deal with the 7 languages of anger
and instead use cooperation.
How this changed my life is because of a time that I got into a fight with my wife.
In the heat of the moment, I said some things I really shouldn't have.
This was right after I had studied Love and Logic for a while and so it was a complete slap to my own face!
I said to myself, "Why am I saying these things to the person I love most in the world? I don't want her to say the same things back to me!"
So I ended up using Love and Logic techniques on myself,
and pushed myself out of the anger languages.
Ever since, my family life has significantly better.
One of the key differences between the anger languages and the love languages is no one forgets an anger language.
Everyone speaks every anger language, in every combination when they are mad.
So I can watch my son get in a fight with my daughter and watch them progress through ALL of the anger languages.
I'll see my son start out using the lecture anger language.
My daughter might counter with distractions.
Now my son tries a combination of intimidation + avoidance (such as running away and slamming doors).
Wow, my daughter just switched to a combo of threats + manipulation + physical anger languages!
Then I'm able to say a few Love and Logic phrases and stop the madness,
such that everyone wants to cooperate.

So to summarize my best advice:
If you can master all of the love languages and get control over all of the anger languages,
then you'll have conquered the most important and hardest parts of life.

I hope this helps you as much as it helped me.

One last thing I must finally note is that Love and Logic never mentions the anger languages directly,
and everyone take away something different.
Some people learn about control while others learn about choices or consequences or even consistency.
Some people just decide to just start using the one liners.
I personally learned about the anger languages through the detailed examples they give.
You might take something different away from it.
Love and Logic focuses on parenting advice,
but their tips and tricks work on the anger languages.