Thanks for starting this discussion on the best way to learn a new language. From my experience, I believe that shadowing is one of the most effective methods to improve your language skills. Shadowing involves listening to a native speaker and repeating what they say as soon as possible after they say it. This technique helps to improve your pronunciation, intonation, and fluency. I learned about shadowing from this helpful article on productive.fish: https://productive.fish/blog/how-to-learn-a-new-language/. Of course, there are many other techniques and methods out there, but I highly recommend giving shadowing a try. It’s a fun and engaging way to improve your language skills!

What language are you thinking off ?
When I started dating my husband my English was very bad. Beside talking with him I wrote him daily love letters 😉 using a Dutch-English dictionary. I didn’t have a computer or even a mobile phone so listening to audio’s was off. So for me it was through conversations, writing and using a dictionary.
My sister worked as a linguist. Prior to moving to Mozambique and putting an Alphabet on the Koti Language she lived for 3 years in Portugal to prepare herself as the translation would go from Portuguese to Koti. She and her family lived in Mozambique for over 10 years following that.
I have 2 nieces who grew up in Africa and are now studying in the Netherlands. They did an online course and now live in the Netherlands studying in Dutch.

Defenetly listening to audio

Sticky notes on your fridge, bathroom mirror work well. Pictures of things like a chair, table etc with the word in that language gives association which helps learning. As does a night you might dedicate to that culture, cook the food from that country, speak the language etc.

Duo Lingo is a free app that I have found very helpful. Daily practise is really important.

An app called MEMRISE
it has so many languages to choose from and has multiple methods to help you learn and even some that make it into a fun game, I am using it to learn Japanese.

Maybe you’d like to give a look at this site: http://www.lifehack.org/608059/how-to-learn-a-new-language-10-times-faster?ref=mail&mtype=newsletter_tier_1&mid=20170705&uid=1036692&hash=797578717f756d7a7371786d4c747b80796d75783a6f7b79&utm_source=newsletter_tier_1&utm_medium=email&action=click

A combination of all, also there are great apps that help.

Some people have an au-pair at home that speaks another language to a child. Not something for me personally, but other people could consider it.

Watching television in original language. Start with cartoons with kids. Then series or movies, subtitled. The best way would be to go and live in a foreign country for a while, but that’s not always possible of course.

I find Audio the best! Too busy to fit anything else in really and great for listening to in the car, which is about the only place I get peace and quiet!

I went to school after work to learn Mandarin Chinese. It was great as you were able to converse with other students who were at the same level as you and your teacher was able to correct you for any mistakes you made.

I second watching movies in that language. It was how a family friend learnt another language whilst growing up his whole life in this country.

Attend a few lessons – in person or online – and then hang out with a native speaker.

A local class would be fun otherwise there are some fantastic apps out there now!

Some of each. Listen, repeat, learn, write and repeat again. Lots of listening and practice

Joining a class might be fun too and you will be able to learn with other people.

Depends on your learning style and commitment to learning a new language. A combination can work, but there has to be plenty of study and revision and using the language.

I think practising it with a native speaker is best! There are some good apps too depending on the language.

Depends on your learning style but immersion in whatever learning style suits you is great.