If you repeatedly keep forgetting flashcards because the material is too unfamiliar, mnemonics can help.
Mnemonics are little tricks that help you associate new, unfamiliar information with stuff you already know. When your brain has something familiar to attach to, remembering becomes much easier.
For vocabulary, you can use the keyword method*. You associate the sound of the target language word with some similar sounding things in your native language. Then you take the meaning of the target word, and put it all into a funny or ridiculous story. Make it as visual as possible (our visual memory is virtually unlimited).
The story will be easier to recall, and from this you can recall the meaning.
Example: the Portuguese (and Spanish) word for mouth is ‘boca’. To remember this, I associate the sound ‘bo’ with the English expression ‘boom’ (as in ‘KABOOM’), and the sound ‘ca’ with the English word ‘cat’. Now I have a boom-cat, who hold a piece of dynamite in its mouth that will explode in a second: KABOOM!
Add mnemonic stories to the vocab flashcards you repeatedly forget (add the story to the backside, try to recall the story from memory on every review).
For languages like Chinese and Japanese, the characters can seem impossible to remember in the beginning.
To get around this, you have to know that each character can be broken down into smaller components (also called radicals)*.
We can associate each of the component with something familiar like an object (in fact, most radicals have a historic meaning you can use). Then we again take those objects together with the meaning of the whole character, and create a visual story around them.
Example: the Chinese character for peaceful (安) is made up of the radical for house (⼧) and the character for woman (女), so we can visualize a story about a woman living peacefully in a house