I learn new words by reading long children books. The repeating same words in different context is the good way to broaden vocabulary. Then I'll try to use these words creating own sentences.

Also, I use program "Anki" for creating flashcards with special scheduling algorithm, where I add words from articles and different web-pages. The cards may include text, images, sounds, videos. There are mobile and desktop version of the program, including the synchronization with a free Ankiweb server for registered users. I find this program is very helpful.

When I should memorize new words in English, I usually make up and write down a short story with new words. I found this useful way in one of the Student books, while I was preparing for English exam in  university. 

I never memorise words artificially. I don't bother to make cards and download multiple apps.

For me personally the best way to make them stick to my long-tirm memory is to hear them in different contexts many times, then use them in speech many times.

When it comes to Russian, I learn better when I drill them, when I do exercises with lots of repetition. Other languages I might try only constant reading or flashcards!

I prefer to learn some new words by reading a book.