I'll admit I find this hard to do. As my thirties approach, I've started thinking I should do this, have this by now. It's tricky to ignore and fight against what society tells you, you should have by a certain time.
When did people stop opening doors for for others? When did people decide that being kind to others was no longer fashionable? The more unconditional "favor" you put forth the more you will get back. The key is to expect nothing in return for a good deed.