I think the best way is to live in the country which uses the language you wanna learn.
If it's not affordable, watching movies and dramas, tv shows could be helpful if you already learned the basic things of the language such as grammar, words, expressions etc.
Or you could make a friend who speaks the language. and you have to try to copy the way your friend speaks. like how the words are used, the expressions, intonation, etc.
I believe the fastest way is to speak everyday with a Native English speaker. Spoken English is very different than written English. If your focus is primarily on speaking, then you must speak it, while listening to it being spoken properly so that you can mimic/learn it correctly.
In addition to the above, it would be good to watch English speaking movies/TV shows to see how it is used.
I think using a language is the best the way to learn how to use it :)
Of course, input is also important. Reading and listening allow you to 1. Learn new vocabulary and grammar 2. See how natives naturally express certain ideas 3. Hear the rhythm of the language.
But if you stare at lists of words and grammar without using them, you won't truly understand how to use what you've learned (active vs. passive). You have to make mistakes and get corrections and feedback.