In general, I try to learn in context, and to read as much as possible so the words just seem normal. To build a larger vocabulary, I use a variety of vocabulary books or other lists, trying either to finish one spread or placing a bookmarker where I've gotten to. I also listen some, preferably with subtitles etc, though my focus is on learning to read. Also, I don't even try at times when nothing is getting through, because of stress or tiredness or whatever; if this happened continally of course I'd need to make some changes in my life.
I only use flashcards when I've tried for some time and the words just aren't sticking; NOT making a flashcard is a wonderful reward for having learned a word.
I investigated yet again software for learning some French and some German words, but...I don't like the work of putting in the words. Premade flashcards or stacks rarely have what I need. I don't like how ugly a lot of them are. I don't like the guessing games that some software features such as multiple choice; seeing wrong answers just teaches me wrong. I don't like my past experience that one software I worked with stopped working and even before had all sorts of bugs. I don't like that I can't review when my computer is off (though that is not super often anymore, and many do let you print pretty cards).
I've decided to stick with my paper flashcards solution: I cut paper (preferably attractive but consistent, and also a bit thick) into strips the width of the paper, using up the whole sheet and ending up with strips maybe 8-1/2 by a bit under 2 inches. I fold them in half so they're now 4ish inches across. On the left in a color of waterproof ink I like I write the foreign word, on the right the English word. I do not give myself clues like using blue for verbs or whatever. (However, I do use different colors of ink and/or paper for different languages.) Then I use them: I review them, making stacks of Definitely Need to Review Again, Don't Need to Review for a Couple Months, and Don't Need to Review for a Long While If at All. If I still am having trouble, I open up the strips (THIS is why I prefer this method to normal flashcards) so I can see both the foreign language and the translation, and study them that way for a while. Eventually maybe I'll play games with them like Concentration or something??
(I also gave a couple samples of a now of course defunct software I used for making "posters" for study:)
