I'm pretty early in the game, but for those who haven't yet figured it out, the easiest way to grind is to maximize the encounter rate, enable auto battling, speed the battles up with the right arrow, and just use your left hand to play.
I guess I only have a few gripes with the game so far:
- Just like the Friend Safari in Pokémon X/Y, this game relies a little too much on the whole social aspect for mundane that aren't related to actually playing with folks.
- Rebuilding Norende reminds me a bit of those silly wait games on mobile phones, but thankfully this one doesn't have that "pay to do it now" aspect. Thankfully, this one doesn't get stale immediately and actually can make you think where you want to invest your villagers, and you don't have to stop playing the game to build it up. I feel bad for the people who can't StreetPass anyone, though. It must be a pain to wait SEVENTY hours to expand the road, then wait even longer to upgrade shops.
- The microtransaction feature to refill Sleep Points seems like a complete joke. I can't imagine anyone actually using it.
Otherwise, the game has been incredibly fun so far. It requires putting lots of thought into setting up your team, and grinding only gets you so far. I look forward to an enjoyable adventure.