I've been a bridesmaid over 125 times. Here are the 7 biggest mistakes I've seen people make before their wedding.

• I've worked as a professional bridesmaid at over 125 weddings in the past seven years.
• Wedding planning can be difficult, but you shouldn't stop communicating with your partner.

When I started working as a professional bridesmaid over seven years ago, I realized how many different details and decisions need to align perfectly.

After working over 125 weddings for strangers, here are the top planning mistakes I see couples make that lead to major problems on their big day.

Not having a worst-case-scenario game plan

Things will go wrong on your wedding day. The couples who think everything will be perfect are often the ones who make the mistake of not planning for the worst.

If your wedding is outside, have a weather backup plan. If your vendors get sick and can't show up, have a list of local options you can call the morning of the wedding. If your guests are stuck in traffic, think of ways you can adjust your timeline.

Rather than planning on the day being flawless, prepare for the flaws.

Forgetting to set a drink maximum for you and your partner

Even if you and your partner both love to party, you should think of your wedding as a marathon. You want to make sure you're not wasted during the first hour and passed out before dinner is served.

After seeing so many couples get too drunk, I started telling all my clients to set a drink maximum they're both comfortable with before the wedding — whether it's two drinks an hour or two drinks for the whole night.

Refusing to talk to a problematic guest

Eyeball your guest list and circle the names of people who might cause problems on your wedding day.

Who are the people who might get too drunk, talk too much about politics, or find themselves getting into spontaneous fistfights?

Even if it feels awkward to chat with them beforehand, you can't just hope they'll be well-behaved. Ask them to be respectful, or have a close family member or friend take the lead and keep an eye on them throughout the party so you don't have to worry about it.

Spending too much money and going into debt

Weddings are expensive. But couples who dive right into booking their venue and vendors often find themselves overspending and regretting those decisions.

It's a lot less enjoyable of a celebration if you're thinking about how many bills you still have to pay once your big day is over.

Instead, set a budget before you plan anything. That way, you'll have boundaries that can help keep you from going into debt.

Forgetting about the end of the wedding

A lot of planning goes into the ceremony and the reception, but some couples forget about logistics beyond that.

It can be quite a sobering and frustrating moment to have to pack up all your decorations, break down your floral arrangements, and pack the car when the party ends.

Rather than just assuming you can make a grand exit at your own wedding without a worry in the world, make sure you choose a friend, family member, or vendor to lead the end-of-night clean-up.

Not communicating enough about the wedding

Often, one person takes the lead in planning the wedding while the other person just has a general idea of what the day will look like. But if you tell your partner not to worry about anything, they might feel like a guest at their own wedding.

Instead, starting about a month or two before the wedding, commit to weekly sit-downs where you review all the details so you both can be in the loop.

Avoiding conversations about life after the big day

It took me a few years of working as a professional bridesmaid — and getting married myself — to realize that most couples are so laser-focused on planning their celebration that they don't talk about their life post-wedding.

Saving all the tough conversations about marriage for after your big day can be a rough start to your new life together.

Instead, write a list of important topics (finances, career changes, where to live, if you want to have kids) and spend time talking through each one before your wedding.