I'm really glad to see this thread, because I had a revelation recently (I think), and I'd love to hear feedback from y'all.
What I've decided to aim for as a "good lead" is to make EVERY follow I dance with feel capable, musical, and appreciated.
That sounds really abstract and philosophical, but it's got to be grounded in musicality, connection, etc, as well as the "smile" comment that keeps coming up.
Capable: For her to follow successfully we have to be clear but not forceful with our leads, and cater to her own specific strengths and weaknesses- not lead anything too difficult for her given her experience & ability. I think this is most important when I'm dancing with a follow less experienced than me.
Musical: Obviously dancing on beat, hitting breaks, and phrasing, but also setting her up so that it's natural for her to hit accents if she's the kind of follow who does that, and varying our own stylistic elements to lead her to whatever song is playing rather than just doing pattern to pattern to pattern.
Appreciated: Some follows already know they are capable and musical, so we need to show we appreciate that and really showcase her talents during the dance. Set her up for play, try to match or complement her own unique stylings and variations. Challenge her where you feel she can handle it. And, of course, smile and thank-you.
I think having fun is also really important, and I tend to be a very playful and musical lead. But I realized very recently that I was more focused on entertaining and showcasing my own abilities rather than my follow's. I'll still do one or two dances a night with a follow I know well and just let the performer in me run wild, and I still do a few of my own syncopations and variations to match the music in every dance. But now I'm really trying to trust my follow and focus on her more.