Is there a way to selectively organize "My Vocab" lists?

I find the "My Vocab" lists very useful.  But as these lists get longer, they start to become unwieldy without some way of organizing them into folders.  Is this possible? Or do the lists just become longer and longer as I add new words.  

Thanks

Have you thought of adding these words to flashcards instead of the "My Vocab" list? That way you can review them separately, and de emphasize the ones you finally learn. A Spaced Repetition System like Anki, or even with pencil and index cards is especially helpful for me, especially if I use the entire sentence on the card to learn a troublesome word in context.

Thank you, Dan, for the flashcard idea.  Perfect solution.  I have not heard of Anki before, but I'll check it out.  I also use index cards, but sadly I have poor handwriting and often cannot read what I've written.  I appreciate the tips. 

I agree. good idea
 

Also, to really learn how to use an SRS (spaced repetition system) either with Anki or physical cards, I recommend reading the Fluent Forever book by Gabriel Wyner. It completely changed the way I learned new words and phrases.

An opera singer and polyglot who writes a book about learning to hack your brain to become fluent in a foreign language has got to be worth a read.  Thanks for the useful recommendation.