Whether you adopt an infant, a toddler or an older child, there is a moment of transition when he or she ceases to belong to a former life and begins to belong to a new one - the one with you.
The circumstances of your adoption process may be similar to others, or they may be unique. Whatever has happened before your child actually crosses your threshhold and walks into your life for good, you'll want to commemorate the moment when your family expands by one.
There are many wonderful traditions already in existence which may speak to your heart as a way of welcoming your child. A family who adopted a baby from China incorporated into their adoption ceremony the traditional Chinese story that those who are destined to meet are connected at birth by a red thread. Since red is also considered to be a lucky color by the Chinese, the theme for the adoption ceremony was clear and beautiful. Some adoption rituals already exist, such as those outlined in an article at Adoption.com, and they may be exactly what you're seeking.
But perhaps you'd like to create your own unique ritual and a ceremony to welcome your child. Some internet research using basic search terms, such as the child's ethnic heritage or place of birth, can yield ideas for unique, personalized adoption ceremonies. Read about the culture of the country where your child was born or, if your child was born in the United States, read about the birthplace. There is always something new to be learned, even if you live in the birthplace and think nothing about it could surprise you. Something could. For example, a man who has lived in Atlantic Beach on Long Island for fifteen years was surprised to learn, after some internet searching, that the big sandbar that forms Atlantic Beach was actually created by man in the early twentieth century. That may not be the basis for an adoption ritual but, then again, it could be. Think about the effort involved in that creation! Somebody must have wanted that to happen, and wanted it badly. Whoever conceived of that idea probably had some hurdles to clear with zoning commissions, planning boards and local government officials, not to mention the sheer organizational details that must have been involved. Does any of this sound similar to the hurdles that adoptive parents must clear before the joyous day finally arrives?
A ritual can be based on anything that resonates. With the adoption of an older child, the Atlantic Beach father could hold a ceremony on the beach, standing on that created sandbar, welcoming his child into a new life after a long adoption process. He and the child could scoop up some water, pour it onto the sand and, together, form something new. A sand castle or a mudpie; it really doesn't matter.
There are no rules about creating new rituals. Read. Reflect. Listen to your heart. After a while, an idea will come to you about the perfect way to symbolize your child's new life with you.