I know it's not recommended, but I made a single page Note Type, and just put them on there:

<b>Be Happier</b><div> </div>Interpersonal: Give the people around you opportunities to be generous. Ask them for favors.

When it comes up, I quietly read it out loud to myself. I've found that seeing these cards often enough keeps their concepts on my mind, so when I go out with friends and someone offers to buy me a beer, I accept it and thank them, instead of refusing even to the point of awkwardness (as is my natural inclination).