I keep things fresh by changing up villagers and collecting their photos. It makes me log in every day to give them gifts. Most days I'll just do a few daily things and that's it. I'm not bored with the game at all but I think forcing myself to do too much everyday and rushing to finish my layout would turn me off the game, so I only work on stuff like that when I'm really inspired to.
But taking breaks can be good, games shouldn't feel like a chore.