What are the three best tricks in life?

 Some important hacks I've learned during my life:

• Always carry a pen with you, especially when travelling (you know that sometimes you will have no other option)

• When you see an animal cross the road, make it a point to stop, look, and wait. There will probably be a few more animals in the sequel.

• Use your foot to prevent your phone from falling if you knock it over (never try this with the Nokia 3310, you can seriously injure yourself)

• As you gather with family, discuss common scams and life hacks that you know but don't.

• If a guest or host asks you if you'd like to take any leftover food they've made home, always say yes. It will probably make them very happy.
• Answer the door with a coat. If it's someone you like, you can say they just got home. If it's someone you don't like, you can say you were leaving.

• If you're selling something on eBay, make a free delivery and add the cost of delivery to the main price.
• When sending a long string of numbers to someone, divide it into groups of three/four digits separated by spaces, so that it is more readable.

• If you solve a problem that you yourself posted on a forum, add the solution so that others can use it for the same problem.
• Don't take other people's business more seriously than they do themselves.
• If someone is introducing you to a song they really like, don't talk during the song unless it's something about the song or something urgent. This song can mean a lot to the other person, and talking in the middle of the song shows that you think your ideas are more important than the person's.
• Pay attention to the smell of your home when you return from travel - it's how it smells to guests all the time, you've just gotten used to it.
• When offering your condolences to someone grieving, focus on the PERSON and avoid talking too much about who they have lost.

And lastly...

• If you read a genuine response on Quora but thought you didn't deserve a positive vote, don't cast the vote. But thank the person for writing the answer (you know how, right?)