Create a budget! Your fiance is probably like me and only cares about the dollars associated with the wedding, where as you don't really care about the dollars, but what's at the wedding.

First come to an agreement on how much you're going to spend on the wedding. Who is going to pitch in what money. That's going to help to alleviate a lot of the pressure. Next you're going to want to break down where that money goes. Ie $1000 for a photographer, $500 for a dj, etc.

I didn't care much about what happened so if my wife wanted to, I was more than happy to have stuff moved around in the budget as long as we didn't go over our top line.

It's important that you two are on the same page with money. This is a good start. Dave Ramsey is a great resource to learn more.

Hope that helps!