If you can remember your own childhood, have ever observed children or even watched them playing with Furbies and learning Furbish, you will know that children have an extraordinary capacity for learning language. The last time I read anything about the National Curriculum, it had been recognised that waiting until children reached the age of 12 before starting to teach them foreign languages was a bad idea. I don't know if any change in practice has resulted, though.
I was lucky enough to go to an enlightened junior school, and was introduced to French at about age 8 or 9. We were trundled into a special room kitted out with a reel-to-reel tape recorder and a projector. The course consisted of pictures being projected onto a screen and the corresponding speech being played from the tape. It was a graphic novel, with the speech bubbles replaced by audio. We looked, listened and repeated. The teacher explained the vocabulary and went into aspects of grammar as they arose, but as far as we were concerned, we were being told a story. We didn't really realise that we were learning anything at the time. The title of the course was "Bonjour Line"
My family moved house part-way through the course, I moved to a different junior school, and I didn't study French again until grammar school. We started again with the same audio-visual concept, topping it off with two years of book-based French grammar, taking us to the "O" levels.
After "O" levels, I didn't make any effort to maintain my French skills. But 33 years later, on moving to France, I was able to make myself understood, could talk reasonably fluently and had a vocabulary sufficient for ordinary purposes. I put this entirely down entirely to the Bonjour Line course: the German that I also studied to "O" level has almost entirley disappeared.
I have never found anything better than the concept of listen and repeat for improving my French. The nearest thing to the Bonjour Line course that I have found is the graphic novel, although the speech bubbles are witten rather than spoken. I find that the combination of pictures, storyline and context mean that it is easier to remember new vocabulary as it is presented.
For speaking practice, there are various publications in which an audio version of the text is presented. I used to use a publication "Champs Elisées" now no longer available, that offered commentary on French current affairs, culture, history, tourism and other things. A free piece of software called Audacity allows you to slice the speech up into manageable pieces, and will replay them as often as you like while you practice repeating it correctly.
My enjoyment of the graphic novel has been rewarding in itself. I am reading an excellent adaptation of the story "Do Androids Dream of Electric Sheep?" by Pilip K Dick, that was also the idea behind the film Blade Runner. The book is much more profound and subtle than the film (as is often the case). The graphic novels behind the film "The League of Extraordinary Gentlemen" are similarly fascinating, and I am delighted by my graphic bio of Jimi Hendrix. I am now reading The Watchmen, in English this time. And so the ripples spread.