Good points, especially Amy's.
Look, I was the most laid-back bride ever. Some of it was probably my personality, but some of it was certainly my attitude. I also agree that most wedding stress is self-inflicted. I barely stressed at all, and not over any of the typical things that brides stress over. Here's some tips, both from my own experience and from 3 years of talking to people on these boards:
1) Like Amy suggested, figure out your priorities and focus your time and budget on them, rather than trying to have the best of everything and spreading your resources thin. Unless you have unlimited time and money and your day-to-day life stops until your wedding, you're not going to be able to do it all, so focus on what is important to you and your FH rather than worrying about everything.
2) Choose professionals that you trust. Then step back and allow them to do their jobs. For example, I did not choose the photographer with the prettiest sample photos, as anybody can take some good photos and display them well. I chose someone with whom we 'clicked', someone who seemed pleasant to work with and trustworthy as well as professional.
3) Don't sweat the details. Put down the wedding magazines and step into the real world. Yes, displays in wedding magazines where the napkins perfectly match the sashes on the BM dresses are beautiful. In real life, however, wedding guests rarely notice or care. Is it really worth it to spend 3 months looking for the perfect fabric to make your own chair covers when you could rent ones that ALMOST match and then spend those three months living your life rather than stressing about chair covers?
4) Don't live your wedding. Yes, it is important to you - but remember that nobody (not even the groom) is as invested in the details as you are. Your friends and family want to talk about things other than your wedding every so often. Your FH might like to go on a date without it turning into a wedding meeting.
5) Please don't approach your wedding with the attitude that it is the most important day of your life. Yes, it is a big day, but it's not all downhill from there! With this attitude, not only will you be putting additional pressure on yourself for everything to be perfect, but you'll feel pretty let down after the wedding, even if everything goes perfectly.
6) There is no wedding bible. Be aware of etiquette, but remember that the entire point of all these complex etiquette rules is to avoid hurting people's feelings. Keeping that in mind, there are sometimes cases when etiquette rules should be bent in order to avoid offense. An example from our wedding: though married couples have to be invited together, a friend of mine's husband was deployed and she doesn't like reminders of the fact that she is alone and he is in danger. So we didn't put his name on the invitation, because we knew that doing so would upset her. This is also true for non-etiquette situations. You do not NEED a combination of three colors just because magazines do it. You do not NEED a limo because most people get one for their weddings. You do not NEED to wear a white dress, dance with your father, or serve champagne. These things are NOT rules.
7) Realize that things will come up. You do not need to make a backup plan for every possible thing that might go wrong, but think about some of the things that are likely to go wrong and how you would react. Freaking out won't change anything and it will make you look like a brat. If something goes wrong, take a deep breath and think about the best solution. Or let the people you've hired deal with the problem. If the cake falls over, the bride does not need to clean it up.
8) Don't stress yourself out by looking at wedding planning timelines and realizing that you're 'behind schedule.' These things are guidelines only - and most of the time, there is no reason to do things as early as they suggest. Heck, some of them suggest that you have your venue booked a year and a half or two years in advance. I wasn't even engaged that long, so how could I book my venue that early? And guess what - everything got done. Follow your own schedule, and don't worry about what brides.com or the knot says you should have done by a given point.
9) You are probably a busy woman, with or without having to plan a wedding. Your time is precious. Don't try to do everything in person. For example, you don't have to visit a vendor in person to get their prices. Any vendor worth doing business with will provide you with some information before meeting them in person (sometimes this takes a little convincing, as they WANT to get you there in person and make the sale). But why should you waste your time looking at vendors you can't afford? Why should you waste your time on an in-person meeting with your photographer what you need to discuss can be discussed via email? I met ONE TIME in person with each vendor. If they needed me for anything after that, they had to email me (I would recommend email over phone communication because you'll have a paper trail. That way, if there's a discrepancy somewhere, you can pull up an old email and say, 'You told me this on X date - here it is.')
10) Make a decision and close the menu. Don't keep looking at dresses, for example, after you've ordered your dress - because you'll just confuse yourself or find something that you like better. Don't second-guess your decisions. Trust that you made the decision for a reason and that it is the right one. Make it and don't look back.
11) At some point, you will reach the point of no return. Stand back, let things happen, adapt to changes if necessary, and ENJOY YOUR WEDDING. Don't stress if the salad is served before the champagne toast, when you had planned it the other way around. Nobody except you will know or care.
12) Plan the wedding you can afford. Don't try to compete with anyone else, including magazines. Money is a HUGE cause of stress - but if you know your budget, know what you can and can't afford, and STICK TO IT, you won't have any money-related stress or surprises. Why look at 5K dresses when you only have the budget for a 1K dress? You're just going to stress yourself out. Don't even look at options that aren't in your price range. Plan the wedding you can afford and be proud of it.
13) Don't stress about anything if your wedding is more than 6 months away. You have tons of time.
14) Don't stress over decisions at all. Nobody will know the decision you didn't make - they'll only see the one you picked. You are the only one who will be comparing your dress to the dress you almost bought. Everybody else will just think you look beautiful.
15) Be flexible. So your ideal venue and church aren't available on your ideal day. It's not the end of the world. Either pick a different day, or pick a different venue or church. End of story. Your wedding will be special regardless of whether it's on a special date or in a special location - if you can't get the 'special' stuff, don't sweat it. You'll just have new special stuff.
16) Don't make any key decisions two years in advance, including your wedding party. Brides frequently change their minds on everything from dresses to food. And a lot can happen between friends in a year or two. Go ahead and think about it two years in advance, but don't ask anybody or book anything until (at the earliest) a year ahead of time. If you don't believe me, look through the posts about BMs in this forum. There's ALWAYS at least one issue with WPs, many of which are due to the bride asking people too far in advance.
17) Prepare for the marriage, not just the wedding. The wedding isn't the important thing, after all. Don't neglect your relationship or your marriage prep. It's not all sunshine and roses, and the more you discuss things ahead of time, the better you'll deal with the issues that will come up. Everybody should have premarital counseling. It's not just for couples with 'issues'. It's for discussing the future marriage and giving you ideas on what to talk about and how to prepare.
18) Everybody's family is crazy. You're not alone. And weddings tend to bring out the craziness. Also realize that your normally crazy family will not be perfect just because you're getting married. A sister or FMIL who has never liked you will not suddenly be your best friend or bond over your wedding. Weddings tend to magnify issues that already exist, and they don't mend relationships. Expect that.
19) Know the things you can control and those you can't. Scenario A: DJ plays the wrong first dance song. Ok, this you can control. Correct the mistake and have him play the right song. Scenario B: Best Man gets a flat tire on the way to the ceremony. Not much you can do about this one. Just send someone to pick him up and let the guests know that the ceremony will begin 15 minutes late (or whatever). Don't stress about the things you can't control.

Vice President and Guardian of the Toilet Brush of POOP: People Offended by Offended People