Hi…I’m gonna also share my two cents, maybe it will help you…I also agree with what other users wrote under this post (specially giso)
What I’m going to tell you a little bit depends also on your goal…are you preparing for better speaking for some sort of exam or for just day to day English speaking? For exams, I guess you better have some strategies…'cause you wanna sound authentic and original, but still you have to show the examiners that you are quite aware of the exam and its rules (for instance, a speaking part of an exam might want you to showcase using different grammatical points, etc).
But from your post, (maybe mistakenly) I assume that you want to improve your day to day English speaking…and if that’s your goal…I share a few things that might help you: So, like other users said, listen to a lot of news and series and movies that you like how they talk or their accents or the topic that they talk about…for instance, if I’m going to watch The Walking Dead series, I don’t want to imitate that hillbily character Daryl…Cause I don’t want to talk like him, right? haha!
But this depends on if you are comfortable with just watching a movie or a news broadcast all in English and right off the bat listening to it and understanding and copying what they say…if that is not the case, then you might be at other stages in your speaking ability now and other strategies might be more helpful for you now.
If you can follow movies/series/podcasts/news quite easily, good news…but don’t also try really hard to copy everything and shadow everything…the goal is just that you indulge yourself in them…like that it’s not a forced activity and you really want to do it…and you really want to watch them and listen to them…once this is like a habbit for you, for instance you turn on CNN two times a day, each time for like one hour maybe…trust me, if you do this consistently, there is no way that your brain is not going to pick up many things (whether words, expression, intonation, etc.) unconsciously…
Another tip that I would like to say is that…I see some users quite heavily depend on speaking in front of mirror or just recording themseleves…while these are for sure hands-down great techniques, don’t get me wrong, but they cannot replace speaking in front of normal real human beings…and I understand with Covid now, it’s a bit harder to speak with other people…but it’s worth it…so not only do you have to speak tons with real people, speak in long sessions! Two minutes Whatsapp or Telegram recorded voice messages are just not enough for good practicing! Call your friends/speaking partners up or video call them or meet them and speak to them consistenly (at least a few times a week) and for long sessions, each lasting more than one hour…there is an advantage in one on one sessions, because you get to speak a lot more than when you are with let’s say six people where you would get to speak less (but it’s good for listening).
So like I said, speak a lot and long!!! You have to teach your brain to be relaxed while speaking…like giso said, when you try to incorprote a new word in your sentence or say a new expression, you might not get it right the first time, but you have to say so many times that finally your brain gets and then you can say that confidently…you might not believe it, but stress and speaking anxiety have a lot to do with good speaking, and the solution is not “just relax and speak freely”…but you have to do it a lot, that naturally and normally your body and brain act in that manner.