The best decisions I have made regarding money and the wedding was insisting on putting deposits down when I did.
My caterer and our venue were the only vendors that requested I put down a deposit to save the date. Everyone else was lax about it but I pressed the issue. Not only did this satisfy my OCD tendencies, it locked me into a great rate.
My DJ, for example, has basically doubled his prices since I booked him 15 months ago. My caterer informed me that had I not booked them a year ago, the same meal options would be $7 more/per person! Between those two vendors we are "saving" $1700!
I am sure as we shell out too much money on too many vendors, Fi would not consider me frugal, but I am pretty pleased with myself!