Well, I'm going with both. Yes, I tell DD she's smart - she needs some explanation for being a bit of an outlier. And yes, I praise her efforts, and if she announces she "sucks" at something (and at 8 it's usually something like handstands tbh) I tell her no, you just need to practice it. And yes she is getting better at handstands although she'll never join the circus
As a kid I had a) no idea I was smart and b) no idea how to work hard. I always say parents in the 70s had it so easy - did anyone else get the old joke, "what happened to the last 5%?" if you came home with a 95%? Even now I still feel demoralized!!
At least I feel I'm one up in that I'm aware of and thinking about these issues, even if I sometimes get them slightly wrong