Not making a budget. Once you have done your research, you will need to sit down with pen and paper and total the costs of your dream wedding. It is at this point that you will prioritze what is most important to you. Then, you will need to meet with the parents and determine the budget. Be specific about who is paying for what, and put it on paper. With a well thought out plan, you will be able to sail through the planning and be confident that the money will be there. Most importantly, STICK to your budget!