Let me preface this by saying, I've been around my fair share of weddings and have even been in quite a few. I'm also coming up on the second wedding in which I've been asked to be the Maid of Honor--so while I'm not the end all be all expert, I do have a lot to say on the matter.
So, you've been asked to be the MAID OF HONOR in your best friends wedding--YAY! Now what?
Be there for the bride. Whether that's helping to pick out the wedding dress or going through a book bigger than a house (only slightly exaggerating) of invitations, she needs to know you'll be her right hand gal before, during, and after the wedding!
Be honest, but tactful. She asked you to be her maid of honor for a reason. For me, I'd like to think it's because my friends value my opinion and the way I tell it like it is. If she asks if the veil makes her look like a cupcake (and it does) TELL HER! Do NOT let her walk down the aisle looking like a Bavarian fruitcake. If she asks you what your opinion is on which shade of grey you like best, give her your opinion or, if you don't have one, tell her nicely that all grey(s) look the same to you.
Be prepared to make a speech. To be honest, this was the worst part for me with wedding number one. I had to have the best man, his wife, my boyfriend, a two glasses of wine hype me up to get through it. It went off without a hitch and people laughed at my jokes, by the way. But man, I was so nervous. Oh and PRO TIP, don't wait until the last minute.
You might have to deal with stubborn bridesmaids/family members. That's just life. There will ALWAYS be someone who doesn't want to wear this or that (literally in EVERY wedding I've ever worked, observed, or been in). Rather than letting the bride be stressed about "Suzy" who won't get in line, put on your MOH hat and tell "Suzy" what's up.
Be on call. With my first MOH wedding, we lived in separate cities, in different states. I can't tell you how many times I got random texts out of the blue about wedding details and my opinion on them. Be there for your bride-to-be even if you can't actually be there.
Almost every bride will have a "bridezilla" moment (or two). Learn to roll with it and put out those fires before they start. Also, know that it's nothing personal.
Don't flake at the reception. Party it up girlfriend, you earned it. Have yourself a glass of wine or bourbon on the rocks, but don't forget to check in on the bride every once in a while. After all, who else is going to hold her dress while she pees or dance the Wobble with her.
Have you been the MOH? What would you add?