The rehearsal dinner is a relatively informal get-together next to the structured formality of most weddings and wedding receptions. As such, the procedure for toasts is not strictly dictated by traditions; the father of the groom, who usually hosts the event, speaks first, and then the floor opens to anyone who wants to congratulate or honor the couple. Many people speak spontaneously, without preparing anything at all, while others prepare a toast beforehand.
Make jokes. Tell a quick, funny story about the couple, or share some humorous marriage advice if you are married yourself. Keep the tone lighthearted.
Be kind to the bride and groom and their families. Don't tell stories or make jokes that will embarrass them or reveal surprises or secrets.
Thank the bride and groom for including you in their ceremony. Tell them that you appreciate the honor and that you'll be proud to stand with them as they take their vows.
Keep it short. Rehearsal dinner toasts should be under one minute long. Finish with a line like, "To your lives together" or "To your love and commitment to each other."
If you are the father of the groom, thank the parents of the bride for organizing and hosting the wedding, and welcome your guests to the rehearsal dinner. As the host of the event, your toast should focus on thanking everyone for coming and for participating in the wedding.
Don't talk without thinking. Even if you are speaking spontaneously, run through what you want to say in your head before you begin. Make sure you're not going to offend anyone or break the tone of the event.