With all due respect, IMHO, I think some fairly prominent psychics like Sonia Choquette and Sandy Anastasi may disagree with you about Tarot cards. Although I haven't used them myself, they are apparently a good tool for focusing your mind and are supposedly a good development tool as well. I think the secret is to sense the meaning of the cards that are drawn rather than to apply a meaning defined by a book.
Having said that, I prefer to develop my skills without having to rely on any physical objects.
Just my 2c worth.