The oldest was a voracious reader from very early on. Headstrong and made lots of mistakes but is now a successful ice cream entrepreneur.
Middle child was/is mathematically gifted. Kept him in sports - hockey, soccer, track, snowboarding - to balance the intellectual and keep him from getting bored. He's now a developer at a startup.
My youngest turned out to be the weakest intellectually. Always struggled with school. But she worked hard (unlike the other two) and was always creative. She is now a UX designer at a big consulting firm and will probably do the best of all three because she learned how to work hard and has a flare for design that resonates.
You can never tell what path they will take, so just encourage them whenever they show interest in something - even if it's not what you're into.