Select an appropriate photo of the birthday girl and print one photo for each of the sweet 16 invitations. Choose a photo that reflects her personality from the past or present, or make a small collage of pictures to fit on the front of the invitations.
Choose blank cards in the birthday girl's favorite colors or to match the theme of the sweet 16 party. Glue one photo to the front of each sweet 16 invitation using the glue stick. Center the photo, if desired, or place it to one side and leave the opposite side open for decorations.
Create a caption beneath the photo, if desired, using the calligraphy pens or markers. For example, you could write, "Happy Sweet 16" followed by the birthday girl's name or any other greeting you think is appropriate. Use a pen or marker in a color that compliments the blank card colors.
Stamp the front, inside, and outside of the sweet 16 invitations using a rubber stamp and ink pad. Choose a rubber stamp that matches the theme of the party and captures the personality of the birthday girl. Use more than one rubber stamp, if desired, to decorate the invitations.
Write a message on the inside of the sweet 16 invitations, which includes the name of the birthday girl, the address of the party, the time of the party and any special instructions, including RSVP information. Begin the message with the words "You are invited to a sweet 16 party for..."
Place each of the invitations into an envelope that matches the card colors. Address them properly and add a rubber stamp to the outside for aesthetic appeal. Mail the invitations or hand them out, as appropriate.