Shaped cards are literally cards that are shaped to resemble something other than the standard square or rectangle. I have seen cards cut to look like teddy bears, castles, cars and even a big pencil. You are only limited by two things - your imagination and the need to retain a goodly section of the fold between the back and front of the card.
1. Decide on the size of card you wish to make and source an appropriate piece of cardstock. Score and fold it in half as you would for a standard card.
2. Using a pencil, draw an outline of the shape you wish to cut. Remember to include a portion of the fold in your design or you will end up with two separate pieces of cardstock rather than a folding card.
3. Use a knife or scissors to trim away the parts of the card you don't need. As you can see, I decided on a three tiered wedding cake for my card. It's a nice simple shape that allows for quite a lot of the fold to be retained.
4. All that's left now is to decorate your card!