3 Answers

Drive them to their hockey games ... cheer!

Drive them to their soccer games ... cheer!

Camp out in the living room and watch sports on tv  .... cheer!

Help with homework.  Teach them cool things.  Teach them how to cook Chinese food .... cheer!

Listen to what they have to say.

Be there for them every day.

Support their kooky ideas and their life choices whatever they may be.

As they grow and become men be the biggest cheerleader you can be.

You do these things and you will be a great friend.  They will love and respect you.

These are the things my Father did with his step-sons plus more.  They have a wonderful relationship. 

The same things they would do with their sons. 

Treat them as if they were actual sons.....