I read Tarot and other types of cards (playing cards for example). I'm not sure exactly what you mean by "gypsy card reading." Gypsy is a culture and race of people. They do notnecessarilydo divination.
Practice is a lot of it. It helps if you trust your intuition as well, because that helps give a deeper reading. Try not to just copy down the meanings of the cards. Try to relate them to each other, creating a story.
You can read many diffferent things with playing cards (or with any medium of divination). The basic definition of divining is finding the unknown. Ideas, feelings, past, present, future events, etc; these are all different subjects that can be asked about and answered.