the one proven way to learn anything is spaced repetition.
could try flash cards with multiple example for each of your most 苦手な (personally difficult) phrases.
could also try using it in conversation with everyone, even who don't learn/speak Japanese. embrace the awkwardness, as they say.
I'd also like to recommend YouTube channels that teach Japanese phrases using clips from dramas, films, anime, books, comics. unfortunately, Japan copyright law gives corporations the power to create a chilling effect across social media and Japan society as a whole. but maybe you can use this English learning channel by reverse engineering to observing the Japanese explanations for English terms & phrases