Try speaking to yourself in English. Especially if you want to improve your speaking skills and daily vocab. If something comes to mind that you don't know how to say in English, translate it and use it for next time. (A chill and lazy way I guess…)

Read extensively across diverse topics to encounter words in context. Use spaced repetition systems like Anki for deliberate memorization. Keep a vocabulary journal, noting definitions, examples, and synonyms. Learn roots, prefixes, and suffixes to unlock word families. Practice using new words in writing and speaking immediately after learning them. Set specific goals like learning 5-10 words daily. Listen to advanced podcasts and note unfamiliar terms. Use apps like Quizlet for consistent practice. Focus on quality over quantity—truly mastering words through multiple exposures and usage.

Use flashcards with words on one side and their meanings/examples on the other. 

Besides, apps like “‌万词王”‌ (with its real-person pronunciation feature) or ‌“不背单词”‌ (which enforces recall through spaced repetition) are highly effective‌.

Anyway, memorizing words refers to long-term accumulation, and it is wise to review them during short breaks (e.g., while commuting on the subway) to reinforce memory‌.

Use this application.

U can start with your hobby and watch some related videos in English. And maybe talk to yourself like telling the name of a daily object u've seen. I mean linking method really works well.

Good question!

By reading a lot. 

When it comes to vocabulary, there's no shortcut but take every step down to earth.

I recommend reading English books such as Harry potter. And don't try to recite the words on dictionary on purpose for its low efficiency. You just read then the words on the page will slowly live in your mind.