If I were to perform a handfasting ceremony, it would incorporated into the vows, when the couple is making eternal promises. The couple would be asked to join hands. I would begin with a concentration on the hands. A blessing so to speak.
"These hands will hold each other throughout the walk of marriage. These hands will comfort each other in sickness and in health. These hands will wipe the tears of joys and of sorrows. These hands will support each other during difficult times and provide comfort during hardship. These hands will be clasped in times of happiness and celebrations. These hands will nurture one another throughout your daily lives. These hands will love, embrace and pleasure one another, These hands will work hard to provide for one another, These hands will make a house a home.
I will wrap these hands together in order to symbolize the eternal promises that are being made and the binding of two lives together, forever.
And then I would begin the vows.
As each vow is repeated by the groom and then bride, I would wrap the hands, and would say - "and so a binding is made."
When the last of the vows were spoken I would then begin to unwrap the hands and would say "the binding of your lives are not formed by these cords but rather with the promises that you just made. Remember your vows to one another and keep them sacred, for these are the ties that bind.