You’ve both decided that you’re going to write your own wedding vows. So, listen up… It won’t be easy, but it will be totally worth all the effort when you are up at the altar facing each other. Here is the thing, you might be telling your partner by now how much you love him every day. But when it comes to creating your own vows for the big day, it is more than different. First of all the setting is not that relaxed as an all-day-in-bed-Sunday-session-moment. The audience will be following every word you say - and that can feel intimidating. But no worries, here are some tips to get started with the best vows in the world to let your love (and everyone else) know just how you feel. Shout your love from the rooftop. Go for it!

Make it clear with your officiant

Okay, the first thing a lot of people are forgetting is that with Catholic, Episcopalian, and Jewish congregations, and more, you may be required to say all or part of the traditional vows. The officiant has to follow the religious rules, and besides that he needs to be prepared for your vows. Start early!

Agree on a structure
It is a special moment when you and your husband are going to read the vows out loud. You really want to be on the same level, so you prevent a scenario where vows to love you till death and you promise him that you will accept video games during evenings… To walk the same line, agree upon the format and tone of voice that you’ll both use. Will they be humorous or poetic and romantic vows? Will you wait until the wedding? Do read them on an intimate place without the guests? How many words will you use? It is a good idea to figure out the answers to these questions before you start writing.

Inspiration first

To start isn’t easy... Start with research. Look on the internet for examples of vows of your own religion and others as well. The best inspiration you can get is to read others and to turn them into your own personalized words. There is no shame borrowing ideas, poetry, movies and books for your inspiration. Capture words, quotes, and sentences that hit you right in the heart and generate that special feeling. 
via: https://nyweddingco.wordpress.com/2013/11/22/to-have-and-to-hold-writing-your-wedding-vows/

Take notes (in your notebook)

Our first tip is to write everything down in a brainstorming session. Write more than you’ll ever need in your vows. Jot down notes about your relationship. When did you first meet? Where was your first kiss? Where were you when he proposed? Write down all the lovely memories you had during that great holiday or the feelings you got when he kneeled down. Think about the hard times you have gone through together or what inspires you in him. Start taking these notes at least 2 months ahead of the wedding to be sure it will be finished and you’re not stressing out the night before the wedding ceremony.

Don’t forget to include promises. A vow is called a vow for a reason, so the promises can’t be missed.

Say it out loud
Now that you wrote everything down, you can practice to yourself, your mom, your best friend, or if you decided not to keep it secret to your fiancé, practice it on him. This is also the time to shorten your vow to one to two minutes. Pick out the most important things, your promises and personal thoughts and feelings. Make sure you aren’t saying things over and over again. You should also think of your audience who are listening. Cut the deeply personal quotes, insides jokes and nicknames, as the audience won’t understand and will feel excluded. Every time you say it out aloud, make it better. Cut the hard words, super-long sentences and tongue twisters.

Don’t forget to work on your ‘delivery’. Practice in the mirror and look at what your face is saying. What is your body language? Stand straight and use your hands expressively.

Do whatever feels good

These tips are just here to help you write your vows, but don’t forget to do whatever feels good. Do the thing that means the most to you both. Your vows should sound like you, especially when you’re making promises to your partner. Make it you, make it personal. 
via: http://www.brides.com/blogs/aisle-say/2014/11/wedding-vows-keepsakes.html

One last tip: make a copy of your written vow. Use a nice note card or a notebook that matches the theme of your wedding.

We really want to share two of our favorite vows that made us smile and realize that you should cherish the one you love.

“Our open attitude toward finding adventure together in life is something that I cherish. I love it even more when these great experiences take the form of us making up a home-cooked meal together with a lot of great wine and music. I would marry you for your risotto alone!”

“But today I can say that I have had my favorite first. Today I marry the man of my dreams and begin the first day of the rest of my life with you. I feel like the luckiest girl in the world. I’ve called you my favorite for a long time and I promise to hold you as number one in my heart. I promise to love you, to be faithful to you, to be your partner and to always be your friend.”