Using a free online template is one of the easiest ways to make printable flashcards. The website for SEN Teacher has a great resource for making printable flashcards that allows the user to specify sizes, vocabulary, fonts and text sizes, as well as being fully editable.
For picture resources, MES English offers a wide range of printable picture sets, many of which do not have a predefined text. This means that they can be used simply as visual reminders or have words added in any chosen language. The company also provides a resource at ToolsForEducators.com that allows teachers and educators to create their own handouts, tests, worksheets and games to support their flashcards.
Printable flashcards are available for all levels of study, and they are particularly useful for subjects that require a lot of memorization such as anatomy and physiology. There are several specialist flashcard sets available for these subjects at all levels up to and including pre-med.
Some particularly nice examples are the handy double-sided image cards found at Easy Notecards. This set shows all of the major muscles in the body, as well as the structures of the eye, ear and brain. The set even has cards showing the interior of cells in the body.