You don’t need to go to seminary to officiate a wedding. In fact, depending on where you live, it may take only a few clicks of a mouse. Here’s everything you need to know about officiating your first wedding, from getting ordained to writing the ceremony — and why you’d even want to in the first place.

Not all people have a pastor, rabbi, imam or other religious leader in their life, especially one they would want to handle such a big event. “Because the wedding officiant plays such an important role in communicating these aspects to the guests, many couples ask friends or family to do the honors,” said Lewis King, director of communications at American Marriage Ministries. “They want someone officiating who understands who they are, and who has a past and future with the couple.”

My sister and her husband, Greer and Chris Spangler, were one such couple, and being one of the more religious members of their family, they asked me to officiate their wedding. “Since he is family, the details of his ‘homily’ matched perfectly with our personalities and values,” Mrs. Spangler said. “During stressful moments, it was reassuring to have someone we love and trust standing next to us. A stranger would not have been able to provide that same comfort.”

Mr. King said it was “important to note that L.G.B.T.Q. couples were at the forefront of this trend, since most mainstream churches discriminated against them in the past.”

“Back in the day, it wasn’t uncommon for interracial couples to also be turned away,” he said. “Unfortunately, these attitudes are still around, and it’s sometimes hard for couples to find ministers that will accept them for who they are. Online ordination eliminates the potential for discrimination by removing the gatekeepers.”

If you decide to have a friend or family member perform the ceremony, choose wisely. You want someone who knows you well, will respect your wishes for the service and is comfortable speaking in public. Just because someone’s your best friend doesn’t mean he or she is polished at the podium, so think about who you know who checks all those boxes — and try to pick someone who can make it through the ceremony without crying!

A number of interfaith religious organizations provide online ordination, such as American Marriage Ministries and the Universal Life Church. (Don’t be thrown by the names — even atheists are welcome to get ordained.) The end result is generally the same, and both are free, so pick whichever one you like and apply for ordination through its website.

Depending on where the wedding takes place, that may be all you need to do. “In almost all states, there are no legal hurdles to getting ordained online and performing a legally binding wedding ceremony,” Mr. King said. “The majority of states don’t even require ministers to register with their local government office. Once ordained, ministers are empowered to conduct the ceremony and sign the marriage license.” You can check out A.M.M.’s Legal Requirements tool to see what your state or county requires. New York City is one of the stricter locations and requires you to appear in person at the city clerk’s office to register (and it will come with a $15 fee.) Virginia is the most troublesome state, denying most ministers who get ordained online, but A.M.M. has information on combating this here.

When in doubt, call the county clerk’s office and ask what it needs from you.

Getting ordained is actually the easy part. Crafting an awesome ceremony, on the other hand, can be a bit daunting. Here are a few tips to help get you through the process.

  • Interview the couple — and their friends and family. You were chosen to officiate because you know the couple and can make the ceremony personal. But that doesn’t mean you have to rely on your own memory. Talk to the couple about their relationship, and interview some friends and family too. You should be able to come up with some good stories to work with — how they met, how he or she proposed, their favorite memories together, or even what they love about each other. My sister and her husband, for example, regularly crossed paths for 15 years before they actually met, which made for a fun twist on their story when I officiated.

  • Figure out the structure. Most wedding ceremonies follow a similar pattern, so it’s helpful to use that as a skeleton. Both American Marriage Ministries and the Universal Life Church have online tools and paper packets to walk you through a traditional ceremony. From there, you can adjust to your (and the couple’s) liking. Maybe you want to split up or rearrange a few items. Maybe the couple have decided to write their own vows or have a friend do a reading at some point in the ceremony. Many couples choose to do a special ceremony toward the end, like the unity candle, sand, or wine box ceremony. You’ll need to choose every detail, right down to the words used for the rings or the presentation of the couple, so ask them what they want.

  • Get inspiration. If you’re having trouble coming up with ideas for the ceremony, broaden your search. Ask your friends and family what they did at their weddings. Search around wedding forums on the internet. Or, perhaps best of all, look up wedding ceremonies on YouTube — this can really help you get a feel for the different kinds of ceremonies and the different tones they can take.

  • Write the invocation. The main portion of the ceremony, known as the invocation, will involve your “speech,” and you definitely don’t want to ad-lib it … so start writing down ideas. Many officiants choose to start with a story or two about the couple, then zoom it out to a lesson on marriage. If you don’t feel you are an authority on the subject, you can lean on outside advice to craft this, whether it’s Bible verses, quotations from long-married family members, or something else. Then practice it, over and over again, until you feel comfortable. You don’t have to do it from memory (I had an iPad at the altar with me), but the less you are reading from a sheet of paper, the better.

  • Help the couple stay on track. Since they have to plan every aspect of the wedding, they will have their hands (and brains) full. It’s up to you to keep the ceremony running smoothly: Make sure the best man has the rings, tell them where to stand at the rehearsal and remind them to bring the marriage license for signing after the ceremony. I recommend you mail the signed marriage license for the couple, since they will most likely be off to their honeymoon the morning after.

In the end, a successful ceremony comes down to two things: research and practice. The more digging you can do for cute stories and moving anecdotes about the couple, the more personal the ceremony will feel. And the more you run through the ceremony in front of a mirror — or a close, trusted friend — the smoother it’s going to go on wedding day.