Mmmhh... I have in mind the fact that smartphones are here to stay, but still have in mind the traditional comic first. With that meaning, That I think of an A4, or A5 or whatever size of paper, and fill the page thinking of how can I get my message through there.
Yes, I have in mind the new technologies and try to be friendly with my design in that regard. So at the end of the day, my comics are best suited for tablets (Which I can somewhat do a parallel with paper comics). So I always set my WC on a PDF, so anyone who wants to get the 100% experience I Want them to have, they have it there. And if they don't think it's worth the try, then they have tapas or any other plattform to enjoy it the way they want to.
Bu I just love the idea of reader flipping the pages, or turning a picture upside down, looking for elements and details. And I love leaving stuff hidden from them, waiting to be discovered.