For the pineapple crown, use two shades of green felt long enough to wrap around the head. If you can't find felt long enough, just glue two 9x12" sheets together. Use a maker or fabric chalk to draw the long leaf shapes on both shades of green felt, and cut out the leaves, leaving about a two inch straight bottom edge to wrap around the head. Lay both pieces of felt together so that the bottom color peeks through in between the leaves of the top color. Glue together and glue the back seam closed into a crown.
For the pineapple body detail, use white felt and cut out V shapes, and small circles. Use a black marker to make a dot in the middle of the felt circles, and draw V's on the felt V's. Use double sided fabric tape to attach to the dress.