More and more couples have the task of not only blending two families, but blending two cultures, two (or more) languages, two nationalities. A wedding is the symbolization of you joining together and creating your own new traditions. What better way to start than honoring the traditions of your families - with a twist!
The first place to start is by gathering your family together. Speak with your parents and your future in-laws about wedding traditions - be they particular to the family or to the culture/religion as a whole. This is a great opportunity for you to learn about each other! Parents will feel honored to be included, and you will be sure not to exclude special family traditions. Perhaps his mother thinks that it is very important to honor the Jewish tradition of stamping the glass at the end of your ceremony, while your Irish father wants you to incorporate a claddagh ring somehow. Listening to everyone's ideas is the first part of your planning.
Pay special attention to wedding traditions from each of your cultures. Perhaps you will have two ceremonies, one being the typical "American" ceremony and one celebrating Chinese/Persian/Greek heritage. Two ceremonies (and sometimes two receptions!) is the most extreme way to honor family and cultural traditions. Brides often wear separate outfits, and at times, the bridal party must have a change of clothing as well. A less costly way of honoring both traditions is to highlight one culture during the ceremony and the other during the reception.
Blending two cultures throughout the entire wedding can be tricky, but the most gratifying. This demonstrates your commitment to blending your cultures throughout your lives. Highlight both cultures in your decor, your music, and your favors. Do you have Hawaiian roots - perhaps let your bridal party wear traditional leis (the Hawaiian symbol of love) rather than bouquets and boutonnieres.
Sometimes the hardest thing to deal with is if your families speak two entirely different languages. Sometimes this means that only you and your fiances (or gasp, even just one of you!) will be able to talk to everyone at the wedding. Maybe you have guests flying in from Italy, or grand parents that are coming from Greece. Regardless, it will touch your family or your guests to incorporate their language.
If your families speak different languages, think about giving them a "cheat sheet." If they have never met before, make sure that you bring them together before your big day. Don't combine the awkwardness of a first meeting with the inability to communicate! Make sure that your parents know the basics in each language, and practice saying it with them so they know how to pronounce the words. Include wedding-related words too, like "what a beautiful day," "welcome to our family," and "would you like to dance". Think about providing a cheat sheet for the entire wedding (with your programs). Also be very meticulous with your seating chart - trying to place those who can act as interpreters at each table.
The most important part of your wedding is reciting your vows to one another. Include your family heritage (and everyone at your ceremony) by reciting your vows in both languages, or incorporating both languages into different parts of your vows. Perhaps you will recite your vows in English, but your fiance will recite his in Spanish (just make sure you can understand both!).
Programs are another great place to incorporate both languages. Have double-sided programs or create a design that uses both languages in one printing. You may just want to incorporate a welcome to your guests in their language, and an explanation of when you will be using Japanese/Greek/Arabic in your ceremony. Even if you choose to have an entirely English ceremony, explaining the proceedings in another language on your program will make your guests feel special and included.
There are many other areas where you can incorporate cultural traditions and different languages. Start with your wedding website - have a page dedicated to explaining your traditions or have a button that converts to a Chinese version. Hire a planner who is familiar with all of your traditions. There are many officiants out there who now advertise themselves as bilingual. Many MCs or DJs do the same. Hiring your vendors with cultural traditions and languages in mind help your goal of uniting your families, as the officiant and the DJ/MC really set the pace for your ceremony and reception, respectively.
Most importantly, stay true to who you are as a couple. You do not have to please everyone, but trying to incorporate traditions will let everyone feel like they are being heard. Honor how both of you grew up, and you will build a great foundation for your new life together!