but first comes Calm-Abiding practice - and lots of it.
Yes, TIB-ji is right.
In my enthusiasm, I I jumped the gun. Calm-abiding must come first. It is from that place that you can really influence the quality of your awareness (i.e., add a drop of kindness).
Nonetheless, I really think that you can enjoy the experience of returning to your breath. It can be a happy moment when you catch yourself distracted, and I was trying to point that out. Finding that happiness requires knowing what to look for, and appreciating what is actually happening.
Its like going to the museum with an art-enthusiast; they point to a painting that otherwise might have bored you ("Dammit, its just a bunch of shapes and colors."), but when you see their enthusiasm, and see the painting from their perspective, you find that you can now enjoy it too.
Its the same with returning to your breath. It can be just another chore ("Dammit, why am I still distracted?!"). Or you can try to see what is fascinating about it: watch the way your body responds when you "wake-up" from a thought. Marvel at how seductive thoughts can be. Feel wonder at how little control you actually have. As you return to your breath, notice how the fringe of the thought lingers for a moment. Its all interesting stuff if you decide to see it that way.
Also, I like to reflect on the positive kamma that I generate whenever I catch my mind wandering. That's what I meant when I said, "Each waking-up moment plants a seed for future waking-up moments." This is really true. The more you catch-yourself lost in a thought, the more you will catch yourself lost in other states during your ordinary life. If you truly understand this, you will definitely rejoice.

Enjoyment and kindness seem like emotions to me. If I don't feel kindness when catching myself drifting and returning back, should I then pretend that I do? It seems fake to practice "returning with kindness" if the kindness isn't actually genuinely felt.
No, don't pretend. But recognize that the practice only works because it amplifies skillful mental states that you have already experienced at some point in your life. There are different ways that you can tap into those emotions. One of them is metta practice.
Here is something I occasionally do: I will pause in the midst of my meditation and reflect on a moment of kindness that I have performed or received, or I'll even recall someone for whom I have uncomplicated feelings of love (really, that means my 3 year-old niece!). I find doing this for a minute or two will then leave a residual feeling in my awareness which I then bring to my breath/body.
Of course, I don't know how "vipassana" that is, but it works.

With metta,
KN