James Clear’s Atomic Habit is a wonderful book which can truly guide you to develop good habits while at the same time get rid of the bad ones.
But for foreign language learners, if you are truly ambitious, by ambitious I mean you want to reach a native-fluency level, putting in half an hour each day won’t be enough. Use the same analogy as James Clear, puting in your saving account 1 dollar each day might accumulates to a decent amount of money in the long run, but you won’t die a millionare with investment of that scale.
To make truly progress in a shorter time you not only need the help of habit, you also need large chunks of time each day, “atomic” won’t lead you far.
What I propose is a more radical approach with language learning:
In the beginner phase, spending 5-8 hours each day, listening to huge amounts of podcasts, reading lots of books, watching tons of televisions in your target language, ideally you need to keep working like this in a long timespan, maybe 6 months to 1 year. This is your “Primitive Accumulation of Capital”.
In the later phase, spending 1 hour each day keep improving your weakness, this is where atomic habits can truly help. Because you already sit on your capital accumulated in the previous phase, you get much higher interest in the long term if you keep working on it.
To put it bluntly, atomic habits are for amateurs. While you might improve in your area and get enjoyment in doing so, do remember you won’t wear olympic medals if you subscribe to that way of thinking.