The actual pronunciation like that of a native speaker is very difficult to pick. The native speaker is born naturally with that accent, slangs, and speech. An exact match to that language is next to impossible until you live in that country for many years. But yes there are many things which one can do to strike a fairly good communication with the native speaker. Listening to various accents each day conditions your mind and starts picking on the different variations of the pronunciation. Learning different slangs, and phrases belonging to different places can help you become fluent. Learning Idioms can really contribute a lot to your speech eg if a child wants to say “I need to sleep by 9 pm”, then it would be spoken as “ I have to hit the bed by 9 pm”, which does not mean he is physically hitting the bed but this is a way in which some things are spoken.
Watching different kinds of movies, video or web series can help you build up a strong pronunciation just like a native speaker understands. It unravels the actual English pronunciation. Above all, a lot of hard work, patience, time and practice is the key to be good at the English language just like a native speaker. A good conversation is the one which is when you speak, everything is understood by the other person and you are able to understand his expression. Learning accents is not easy but understanding them is way much easy to grasp. All it is need is a good practice. There are many different portals having audios in different accents like a guide telling you about a place that can help you with understanding the local words, a conversation between two people from a different place can help you spot the variation in the pronunciation of two people. Eg. a British accent has rhyming, intonation and very appropriate grammar whereas the American accent will have a lot of contracted words and slangs such as Let’s go will sound like Sko. Each part of a country will have a slight variation of accent. One needs to go through them and observe them carefully before practicing in speech. There is another way to get the same accent as Britisher is online IELTS speaking training.
Another thing that you can do is undergo an English training program that teaches you a Global accent which is acceptable everywhere across the globe and understood by native speakers. They train you by different tongue placements in your mouth to produce different sounds eg when you have to say something that starts with R, they will tell you to roll your tongue and speak, it produces a very different sound. Similarly, to say a word that starts with V, the upper teeth should be pressed on the lower lip, it gives a very clear cut V sound, to say something that starts with a W, rounding the mouth will give the W effect, for saying “ Thank You”, the tip of the tongue should touch the back of the upper teeth, it will produce soft sound ad Thank You will sound like S’ank You and there are many such alphabets that are pronounced with the different positioning of the tongue. All these have to be practiced a lot so that eventually it comes naturally in your speech. Although it takes some time to get that flow.
The next thing that is required is to learn the contracted sounds and joining the two words to sound like one. Eg. when you want to say “I would rather” in a contracted form, then it will be spoken as I’d rather where only prominent sound after “I” will be “d”. Similarly, I am will become I’m, I have will be spoken as I’ve and it will become it’ll. Another thing about a better conversation is putting the stress and pauses at the right places in a sentence. That creates the rhythm in the speech also know as Intonation.
At various places English used is formal and at some places it’s informal. The American people generally use a lot of slangs or shorten the words in their speech eg if someone wants to say “We really had a good time last night”, so an American would rather say it as “ We had a blast last night”. The same thing if said by a Britisher will be more formal like “Yesterday, we had a splendid evening”.
Britishers are very particular about their grammar placement in the speech and they use formal language. They do not use slangs. And there are certain words that are addressed differently in each country eg. in British English its Railway Station and in US English its Train Station. In some countries, a bathroom is referred to as a washroom, powder room. So, one word at each place is spoken in a different way.
If these little tips are continually used in your speech each day for a long time, they become a natural part of your speech and the accent occurs naturally. It may not sound exactly like a native speaker but it will be somewhere near that and very easily understandable by all. Without practice nothing will help, fluency only will come with constant practice.