Birthday Cake Piping Techniques
Piping frosting on birthday cakes takes a little practice, but great beauty is created once the technique is mastered. Make flowers, stars, beads, scallops and write script to personalize the cake for the celebrant.
Frosting
Use butter or butter cream frosting to decorate cakes when first learning. Flow is easy and the frosting is simple to make. Royal icing is another option, but dries hard and is usually not eaten. Frost the whole cake first in order to leave a smooth surface on which to work. 
Tips
Tips allow for different frosting designs on a cake. Tips are made from plastic or metal and look like little cones. The large end is connected to a pastry bag by a plastic connection that looks like a washer or doughnut. The shape of the tip is dictated by the small end of the cone. Round tips have round openings and they are used for writing script, outlining or making dots, beads, lattice and vines. Star tips have round ends with small slits or separations around the edge. They create stars, shell edgings and some flowers. Basket weave tips have a flat opening and the frosting comes on in wide strips that can lay straight or ruffle. Tips come in many different sizes and in other shapes.
Pastry Bags
Pastry bags are clear or white plastic triangular sheaths that open at both ends. Secure tips to the small end and load frosting inside at the large end to about two thirds of the length of the bag. Fold the top corners in and roll the edge of the bag down right to frosting level. Guide the tip by holding the bag right above the connector with one hand, and squeeze the bag with the other hand to create the design.
Easy Designs
Practice piping on a piece of wax paper then on cupcakes before trying to decorate a cake. Squeezing lightly so that the frosting flows continuously is as hard to do as keeping too much from coming out at once. Hold star tip clad bags straight up and down against the surface being decorated. Squeeze until the right size star is achieved, stop squeezing and lift straight up. Place a row at the top or bottom edge of the cake to make a border. Star tips also make pretty little flowers. Just squeeze a little and lift to make a small, flat flower.
To write script, place a round tip on a pastry bag and touch of the cake, squeeze and move to guide the bag like a pen. Stop squeezing, place the tip on the surface and lift to make a clean finish. Use round tips to outline decorations or make a scallop around the side of the cake.
Thousands of variations are easily created with just a few tips and a bag. Experiment with different tips to find what works best. Also check online or in books for other techniques that make birthday cakes works of art.
