Make sure you know these tips before your wedding because it will make it a smoother day when you have these in mind!
Make Sure You Eat

“You will be probably be too pestered by others to actually sit and eat your meal. My wife had boning (support structure) in her dress and it was uncomfortable for her to sit in and eat. We sat down to try and eat and her aunt and grandmother came over and were pestering her to see if everything was going fine. My wife was already irritated from trying to sit in the dress and now her family wouldn’t leave her alone for a minute. So I said, ‘Let’s go to the other room and eat’ and we grabbed our plates and went to the dressing room. I unzipped her dress so she could slouch and eat and we lounged around for about 20 minutes watching college football. That 20 minute break was just enough for us to take a breath and relax before going back to the party. My wife wasn’t irritable anymore and she and I both had a great evening after that.” Source
Something Will Go Wrong

“Something WILL go wrong. It is unavoidable. The car that was supposed to drive us away from the venue after the reception didn’t show up. You gotta just roll with it and realize that the only thing that matters at the end of the day is that you are married to your best friend and love of your life.” Source
Come On Man

“Guests not adhering to the RSVP. Like bringing extra people instead of the agreed upon number. Which in turn brings about shortage of seats and of food. Some weddings I’ve attended had the couple request the guests to not bring kids. Also don’t be nervous! I was so nervous during our wedding that I didn’t even realize that I did not eat through the whole program. It was only in the morning that I asked my wife how the food tasted. Then she told me she also did not touch the food served on our table. We took weeks deciding what food to order for the occasion then on the day itself we didn’t even eat a single bite!” Source
The Real Wedding Reception

“The real wedding reception starts when all of those relatives you didn’t really want to invite anyway go home and you’re left with just your friends. You just raided the leftovers, and the DJ still has an hour that you paid for. He’s blasting a song that would have given Grandma a heart attack, and someone is drinking straight from a champagne bottle because they couldn’t find a glass. You lost your tie long ago, and your wife just changed out of her dress. Finally, after all the ceremony and tradition, it is your night. No one is going to give you unsolicited marriage advice, and you already forgot that offhand comment someone made about the food. It’ll hit you then, through the exhaustion and merriment. You’re married now, and for tonight at least all is right with the world.” Source
Logistical Details

“You will not remember any logistical details after the fact. Did you tip the caterers? No idea. Did you give the marriage license to the officiant? Uhhhh. Basically, have other people in charge of ensuring each of those things gets covered because even if you make it happen, you won’t remember and will scramble around for days after trying to get everything straight. I have deadly allergies. The only time I’m more than 3′ from my epi-pen is when I’m in my apartment. No idea where it was that day. I vaguely know I’d planned to have it on hand on the day of, but I didn’t have any idea where it was.” Source
FYI Grooms

“If you’re the groom, make a point of telling your bride how beautiful she looks. You’d think it’d be something that will come naturally, but that day is so full of stress and events and tons of people, you need to make a point of doing it so it doesn’t slip your mind.” Source
So Children?

“At the reception, MOMENTS after getting married (whether you have kids together already or not) someone WILL ask when you’re having children, or if you had a short engagement they’ll ask if the bride was pregnant. My sister dated her high school sweetheart for 8 years before they got engaged but once they were engaged they did a 2 week engagement and got married at a courthouse on 11-12-13. EVERYONE freaked out and asked if she was pregnant. No, she just wanted that date. I got married after a 2 year engagement and was asked ‘why don’t you have kids yet’ uh.. we JUST got married, like 30 min ago…wtf.” Source
Stains

“White dress + anywhere = stains. Bridesmaids, bring chalk. White chalk. Cover any smudge of makeup from Granny’s hug or that little bug that got squished with a little bit of chalk. I’ve used this so many times I bring chalk to weddings even when I’m not in them. Also, fully expect at least one person you didn’t invite/ RSVPed no and showed up anyway/ said no date, brings date to come to the wedding. Most catering options will let you round the number up to the nearest five without too much cost. It’s worth it.” Source
Wedding Crasher

“Someone who said they would not be at the reception will show up. Make sure you either have a place ready or have other contingency plans. Also, something weather related will probably go wrong, because the universe has a weird sense of humor. In my case, our dog bit my thumb to the bone about 20 minutes before I had to leave the house. Blood everywhere. Loads of fun.” Source
Don’t Feel Pressured

“The biggest thing I can think of is don’t feel pressured into having sex that night. After the wedding you will be exhausted and most likely will have to spend 3+ hours pulling your wife out of her dress and all the sh*t she will have in her hair. I pulled pins out of my wife’s hair for a crazy amount of time after the wedding. For the love of god if your taking a flight the next day for a honeymoon don’t have it be early in the morning. Get some really good sleep that night and then go full crazy on your honeymoon.” Source
Those Are The Real Friends

“Remember to choose bridesmaids and groomsmen who can discreetly handle awkward situations for you. My friends got married recently and my girlfriend and I were both in the wedding. Just like any wedding, things went wrong the day of, but we were able to take care of all the problems without the bride and groom even noticing. One girl at the wedding had a breakdown because of some personal issues. She started crying and ran out of the reception and into the woods (the wedding was in the mountains). Her boyfriend needed help with her, so my girlfriend and another bridesmaid ran after her. Luckily no one else noticed, so it didn’t cause a scene. Unfortunately, her boyfriend was the dj and he was playing music on her laptop. By the time he asked me for help with the music, her computer had gone to screensaver and locked us out. He didn’t know her password to the computer, so the music just kept playing whatever was next on the playlist, some of which wasn’t all that great. It came time for announcements to be made, so I just unplugged her computer from the speakers and hooked in a microphone to do the announcements. However, no one prepped me on the announcements and I didn’t know everyone’s name, so it was awkward when I had to ask for help with some of the people. I stalled for a while until we could get the computer unlocked, and then we were able to continue on with the special dances, including Hava Nagila. Later, after the honeymoon, we mentioned some of the shenanigans that took place, and the bride and groom apparently had no idea all that went down.” Source
Numerous Problems Possible

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“Bad weather, misbehaving children, illness in the wedding party, the building engineer forgetting to turn on the air conditioning, pictures taking longer than expected, wedding guests coming with children when there is no child care available. I’ve seen all of this at other weddings — my wife is a professional event planner and made sure none of that happened (or mattered) at ours. I recommend hiring a planner if you can afford it, they’ve seen it all and can anticipate problems.” Source
Take It All In

“You will be super busy, take a moment and just you and your SO go stand in the corner of the reception hall and just look at everything. Take it all in because it will fly by and you will barely remember it.” Source
Don’t Forget Something

“You will forget something. Make sure it isn’t the $500 cash your husband put in his rent-a-tux coat pocket. We got it back but our best man had to drive an hour back to our hotel to drop it off.” Source
Budget

“The day is going to go fast. Really fast. Give serious consideration as to how much money you really want to spend on something that’s going to seem like it is done in three hours. Very very glad me and the wife changed our plans to a budget wedding. The second we canned the free bar, a lot of our relatives were suddenly ‘busy’ on the day of our wedding and couldn’t make it. Very glad I didn’t spend thousands on a free piss-up for those selfish wankers. Instead, we asked permission for family members who donated for the wedding, to let us re-name it the Baby Fund. This allowed time off work with no worries about drop in pay due to maternity/paternity leave. Money much better spent in my opinion.” Source
Certain Of Attention

“Someone might try to steal your thunder at the wedding, for example someone declaring their pregnancy or engagement, to make the day be a bit more about them than you. Then a lot of the focus on YOUR day will push over to other people. There’s not a lot you can do in this situation aside from try not to invite the jealous centre of attention types.” Source
Sorry Grandma

“Your until now quiet and sociable child will decide that on this particular exact day that hanging out with Grandma is no longer something they really really enjoy but something that they really really hate and will scream bloody murder about at the loudest possible volume for several hours unless they have the undivided attention of their parents.” Source