Make People Feel Valued
Everyone enjoys being complimented. Nice hair. Great outfit. You sounded awesome. These all make us feel good. But similar to a "like" on Facebook, these words last only a while. An even greater honor is showing someone they are valuable.
I have the privelage of working with volunteers on a regular basis. I tell them they do a great job all the time. I also try to convey how valuable they are. Sure, someone else could be trained to do their job, but right now I need them.
We all fear being replaced. That someone else can come along and do our job 3x better than us. That's why showing genuine appreciation and making someone feel valued is the highest compliment.