Interesting, I did bottom up first and then when I started to feel that same itch to actually build something useful things were more top down.

I agree that a mix of bottom-up and top-down is probably best, I was curious about other paths because I found that starting with bottom-up worked really well for me and wondered if that generalized to other people or was just well suited to my learning style. My experience makes me think that a solid foundation is essential but it's entirely likely that's just "that's the way i learned" bias.