Nah, I like playing through the single player casually. Not only that, but I remember doing a Nuzlocke once and I lost in the first 10 minutes.
I usually don't use Exp Share until after the main story is finished. I like to go through at a slower pace and spend time with each of my Pokémon. Not using Exp Share was referred to as a challenge, but I guess it's sort of my own version of casual. One thing I'm going to do differently this time I think is not try to build a team before playing the game based on the information provided before the full release. I've found it's a lot more fun if I just use whatever Pokémon I find that I like, or box the ones that I don't, than to commit to a set team.