Are you making these for yourself? If so, I consider this a bad approach to the language, taking in account that I'm a very conservative person, I think sticking to more traditional learning methods would be more effective. If you want to insist in this flash-card style , instead of new isolated words, put small sentences from books, mangas, daily news, even sentences that you've translated/studied before, so that you have to pay more attention to them and make some effort to comprehend the grammar involved.
In my experience isolated kanji and vocabulary pieces did little to improve my grasp on the language.