Assuming the wedding will just work itself out and not scheduling enough time to work on your wedding details.
Many brides find it very helpful to set up a specific day of the week when they'll focus on their wedding plans. If your engagement is not as long, you may want to spend a couple of days each week or plan several weekends where you can focus on what needs to be done. Staying organized and communicating effectively are essential to staying sane and getting it all done.
Forgetting how many people you can accomodate at your reception site.
As you put together your guest list, think about how many people you'll be able to accomodate for your ceremony and reception site. Your food and beverage budget may also be a factor in who you invite since more guests often means more money.
Waiting too long to choose bridesmaids and groomsmen.
The earlier you decide and ask, the more time you'll have to let them help you plan the details of your wedding. Think through and pick who you will choose to honor as your attendants. Choose individuals who have been your friends through thick and thin and who you'll enjoy spending time with as you plan and prepare. It is a good idea to let them know what will be involved and expected since many of them will be contributing their precious time (helping to plan the details) and hard-earned money (purchasing gowns or renting tuxedos, etc.). They'll be honored by your request and your friendship will grow deeper as they participate in your special day.
Forgetting to take time to relax.
If you find yourself getting stressed out, take some time to recuperate. Spend a day completely away from the planning. Have fun. Relax. Enjoy spending time with your fiance. Create special moments that will deepen and enhance your relationship. Forgetting to focus on what is important will cause you a lot more stress than it is worth. Don't feel like you have to do everything in one day. Pace yourself. Keep things in perspective. Don't forget the excitement that led you to your decision to get married in the first place. Make sure you spend time together and take care of each other in the process of planning your wedding.
Jim and Heather Butler