Off the top of my head:

- Atelier Sophie: 2 achievements are missable. The first one requires completing all of Monika's events. Unlike other characters, some of Monika's events have time limits and thus can be failed. The time limits are very obvious however, just do what she says, she means it. The second missable achievement is tricky, you need to craft a Philosopher's Stone BEFORE beating the final boss. If you manage to do it, you'll see a special cutscene where Sophie discovers a new power. But you won't get any achievement just yet. Beat the final boss, and one more achievement will pop up during the post-boss cutscenes.

- Atelier Firis: only 1 achievement is missable, it requires beating the optional exam boss. It's a rather tough fight, even on easy, make sure to prepare the best possible gear and items. Note that the identity of the boss is a spoiler, so I don't recommend googling it in advance.

- Atelier Lydie & Suelle: the whole true ending route is missable. Basically, you get rank up tasks in each chapter and you need to turn in items to fill a bar. Make sure to fill the bar completely to get a flower stamp. Apart from this, nothing else is missable to my knowledge. But on a side note, this game is hell to 100%, there are just too many completionist type achievements.