Keep an online database or spreadsheet with the names of all invitees and RSVPs. Use the same list to note gifts given and thank you notes written.
Put together a basket of emergency items for the ladies' room at the reception. This includes things like hairspray, clear nail polish for stocking runs, and a mini sewing kit.
Arrange some quiet time for just you and your fiance during the wedding planning process. A romantic date or a weekend away will give you a break from the stress.