How do you learn foreign language vocabulary, beyond Anki?

Can you give an example of the words that you cannot memorize and the sentence they are coming from (with a translation)?

Are those basic words or probably some rare ones? Depending on the frequency of those words appearing again I would suggest either:

• If they are fairly common, add some related words to force some redundancy.

  I use Anki to memorize Japanese vocabulary, and in my case I pick words that share the same kanji than the hard word. For example, the word 図書館 (library) can be made redundant and easier to remember by adding 図書係 (librarian) and 図書 (books).

  Bigger words sometimes are composed of two (or more) smaller ones, which are easier to memorize and also help to remember the original one (I know it happens sometimes in German, but I'm not sure how frequent they are). I guess that you can pick some words with the same roots in German, but I'm not sure how easy is to find them in a dictionary or some other source.

• If they are somehow obscure, it might be better to drop them for now.

  As you mentioned, you are spending much more time on those words than the others and it seems it is not helping to memorize them now. That time could be used to learn other words, and it might be a better use of it. And, if you are exposed to those hard words again in the future, with a bigger vocabulary, it may be easier to remember them by having a more solid base (for example, some words were very difficult to grasp in the past, but similar words now are much easier). Sometimes seeing a word that was hard for me in a different context make a huge difference and I can easily remember them, and it is not just the effect of being exposed to it again.

For simple nouns and verbs, you could use pictures as the prompt? I find this really helpful for building memorable associations, and helps me 'taboo' English on the flashcards.

Another suggestion is to add some kind of personal connection or mnemonic device. I haven't used this myself, but it's recommended in a book called Fluent Forever, which is all about learning languages through spaced repetition.

A little unrelated to you original question, but it seems useful.

I could add "learn to write" to my goals but that seems significantly harder to self teach, because checking my work is harder than looking up the same sentence in the English version of the book.

You can try Lang-8 where some native speakers correct your writing while you do the same for some other users. I used it in the past and the community was very good, the texts I submitted were corrected very fast (it depended on the time I have posted them, but usually less than a day, and sometimes in a few minutes), and most users also added some good comments on how to sound more natural or some suggestions of alternatives.

What's your actual goal here (i.e. what types of things are you actually reading?)

I don't have any experience to offer, but my first guess is that if you're reading, and looking up unfamiliar words as they come, that seems like that'd be sort of a more natural distribution of what-words-to-learn as well as the context in which they appear. (i.e. unless you have a special reason to care, seems like learning words in isolation without context probably isn't that important)

not sure if this would help or not. https://www.youtube.com/watch?v=AbvaITy3oeQ

Basically someone talking about how to use Anki effectively based on his own experiences and what he found he was doing wrong.

It might be not so great as it's about learning medical terms for med school so not quite a new language.

Not sure if you've seen Quizlet before or not. I like that tools it offers. If you have not already looked at that you might take a look. Not sure how easy it would be but Quizlet also allows sharing decks with others so if you have anyone you are learning with -- or are in any online groups for learning German that might provide some options to help.

It sounds like you've already homed in on one of the big items -- relevance and context to you personally.

One last thing, do you speak the word aloud? If not maybe try. That will engage other parts of your brain and so perhaps create more links to the meaning and a stronger memory of the word and meaning.

Last edit... Do you listen to any German language music or watch German language movies/shows?

I'm an avid Anki user, but I don't think I would use it to learn a new language. I think the way I would go about this (I've done this before although I've not really optimized the "method") is to have TV shows or movies with the audio in the particular language you want to learn while having both your native language subtitles and the audio-language subtitles up in the screen (there are actually several programs that allow you to do just this, one is: GOMPLAYER).

This could work even better if you see a TV show or movie you have already seen previously but this time in the language you're trying to learn (this has the downside of not being the natural audio of the show, you already know everything that happens and you miss the cultural knowledge but you can also pay half of the attention you would than if it were a new show).

I do want to note that I haven't tried Anki for languages and since it works quite surprisingly well for mathematics I would be willing to give it a try (for doing this I would use many of the plugins).

EDIT: Since this has been initially down-voted, I want to add that I've done exactly this to learn various languages and very quickly so. I also think it could be a very good complement to learning foreign languages with Anki (without replacing it).