'Raw Smarts' is a slightly odd concept. I'm no psychologist, but I think that the majority of current research points towards the idea that ability in almost anything is essentially a consequence of practice and experience.
I think the real issue is telling kids that they have an innate gift for anything. If you tell them they're smart, there's a natural assumption not to bother working. If you tell them they're disciplined, they won't look for ways to keep themselves motivated.
I'd be more inclined towards saying something more along the lines of "you're doing really well at X" - providing useful, motivational feedback, without implying that no work is necessary.
Personally, as someone who coasted through a lot of school but ran into trouble later (effectively because I'd forgotten how to 'pedal') the two things I would have been most grateful for:
1. Balance. If someone has a facile grasp of e.g. science and maths, don't (from a young age) overly steer them towards specialising in it. Instead, say "for the rest of this academic year, you only need to do a 'maintenance' level of work on science, so we're going to take that time and spend it on areas you're less good at". Of course, this level of personal attention is expensive, because it implies stuff like small classes and high-quality teachers who care - but OTOH I was lucky enough to have those things, but not with this strategy.
2. Challenge. Science and maths were always easy for me, so I never had to work. This is damaging. So there would also have been value in doing the the converse of point (1) - saying "for the rest of this academic year, you only need to do a 'maintenance' level of work on the standard science curriculum, so we're going to use that as an opportunity for you to do harder, more independent work in those areas" and develop a better work ethic and an ability do do things independently. Again, needs lots of personal attention and even better teachers.
We sometimes do OK-ish at (2) - in a fairly haphazard kind of way, and partly because kids tend to do it for themselves - but I can't think of any examples of anyone really pursuing (1) (may be different in different cultures). This is an opportunity, because (1) requires a lot less deep subject knowledge, so is much more feasible for parents to pursue.
Ultimately though, optimising for the top end becomes expensive quite fast, and while it's important to keep pushing the boundaries, I'd much rather the investment was put into improving the state of education for everyone, rather than fine-tuning the path for those who will be at least OK regardless.