1. Be supportive when your friend has bad news.
2. Be supportive when your friend has good news.
3. Don't gossip.
4. Keep a secret.
5. Exchange favors.
6. Don't criticize, don't flirt
7. Be kind to a friend's children.
8. Be friendly to a friend's friends.
9. Show up.
Bonus activities:
10. Remember birthdays.
11. Be nice to their pets.
How to make true friends -part 7 - How to be yourself
How to make true friends–Part 6 – Attracting the friends you want
How to make true friends - Part 5 - Get out of self deprecation mode
How to make true friends - part 4 - Body language
How to make true friends - part 3 - The art of honesty
How to make true friends - part 2 - The pride of loneliness
How to make true friends - part 1 - know yourself