Choose vegetables that are soft enough to be penetrated but firm enough to hold their shape, such as potatoes, radishes and pumpkins.
Sketch details on the vegetables, such as eyes or other features, using a pencil or marker.
Cut thin slices for creations, such as flower petals, using a peeler. For example, if making a flower bouquet, peel a carrot on the long side by holding the peeler against the carrot and sliding down slowly, peeling away a piece a centimeter thick. Stack two or three pieces and carve the shape of the petal, repeat for multiple petals, then attach petals to a stick or skewer.
Create layered pieces by using toothpicks to keep vegetables in place. For example, to create a Christmas tree, use a squash as the base, and stick broccoli pieces into the squash, all the way around, attaching with toothpicks. Add some color by stringing cherry tomatoes around the tree by threading them with a string. Using a brightly colored vegetable, such as a pumpkin, cut a star shape and set at the top of the tree, attaching with a toothpick.
Use stand-alone vegetables to carve animal shapes. Choose the animal based on the shape of the vegetable. For example, use an eggplant to create a pig. Lay the eggplant flat, and using a peeler, peel two half-inch pieces, with an inch separating them, upward, so they curl and resemble pig's ears. Do the same toward the bottom of the eggplant for the tail. Carve eyes, and attach four toothpicks for legs.