Collate resources, videos, songs, diagrams which have helped you.
Sometimes an image or rhyme is all you need to fully understand a complicated concept.
For me, the difference between the German Accusativ (motion towards) case and Dative (in one place) case was perfectly summed up by a nerdy video made by some american school teachers.
In order to explain the difference, they first showed a shot of
"Ich schwimme im Bad" - I swim in the pool.
(man swimming in pool) DATIVE
they followed it with
"Ich schwimme ins Bad" - I swim into the pool.
(man dragging himself slowly along the concrete and into the pool) ACCUSATIVE
Silly yet illustrative and memorable videos, images, and songs seem to work very well in the context of language learning.
What examples have you come across?
What would be the best way of organizing them by merit (likes, votes) and subject (language, grammar, parts of speech)?
Sometimes it might be possible to adapt an idea into different languages -in the case of my swimming example, many languages have the dative and accusative, and this explanation could work well for all of them.
How could we go about making it easier to adapt and remix explanations between languages?