The best way to learn a language is to be a young child and just absorb it.
There are memory techniques for learning languages but, really, if you lack a child's memory ability, then I do not see how you can learn a language rapidly without...
Already knowing a similar language. Romance languages seem to be fast-to-learn for people already fluent in a Romance language. Or reading Japanese characters might come quicker to a Chinese student than to a Western student.
This is a really frustrating conclusion. When I was younger, I believed the foreign language learning lessons of the many memory books I was reading; but, having spent a lot of time just trying to learn the basics of some European languages, I see those techniques as being helpful on occasion but of limited application. It's best to be a young child; otherwise, you have a lot of work to do.
I think that, if a vocabulary word is resisting your attempt to memorise it then a memory technique is good. But language communication takes place at such speed that there is no substitute for rote learning language.
I do like the idea of gently learning the first 100 words of a language by playful memory techniques. If you think the Mandarin word for China sounds a bit like John Wayne, and that helps you to remember it then great!
I also think that, if you are given time to pause, and you have a memory technique for recalling a word which you want to employ, then a memory technique would be good then too.
One of the systems of images of this course is 1000 items. I made those items be useful vocabulary. It would be a good test to see if you know comon vocabulary if you run through the list and test if you know a foreign word for that vocabulary term. Or you can imagine an image that represents the first letter of the foreign word; and imagine that image in a story with the vocabulary image: a way to memorise the first letter of the foreign word.
I also have a plan to expand the vocabulary items into short sentences where the vocabulary item from the 1000 list is the 'object' of the sentence; and then you would learn the short sentences of subject, verb and object; then the revision would be of more than just the 1000 vocabulary items. I could call it 'vocabulary triads'.
My word prompts for foreign language are only 2 letters long (ie. the AA-ZZ system of an earlier lesson). I do wish I had a system for common 3 letter syllables too. Eg. I'd rather associate 'con' with a word which begins with 'con' that to merely associate 'CO'. (See the CVC Consonant Vowel Consonant article.)