Before you head to the grocery store, do your best to calculate how much of each ingredient you need. When scaling up a recipe, be sure to scale by area, not diameter of the pans. Make a list, and then buy one extra container of everything. You can always return unopened groceries, and you'll be so glad if you don't have to run out for more ingredients at the last minute.
It is not so uncommon nowadays to find someone enhancing his/her own wedding event cake. In fact, it is a practical suggestion especially to those that have an extremely tight spending plan.
My fiance and I love the idea of a day-of-the-dead themed cake. We love all things fiesta related but would tone it down as our theme is more romantic/vintage we thought we could paintly bright flowers, make sugar flowers and have some colourful pansies to cascade down the cake. Top this with bright peonies, colourful ribbons wrapping each layer and lots of pom-poms for a riot of colour!
You should use a recipe specifically designed to be a wedding cake as it will ensure that it is sturdy enough and that it makes the right amount of batter and icing. For a three-tier cake, you need to make three cakes of 12", 9" and 6", as well as a massive amount of icing. Most three-tier cake recipes have a step-by-step schedule for when you will need to bake and assemble each part.