I recently was commissioned to do a collage for a 40th Wedding Anniversary. The only directive I was given was that it not be "too girly" or too large to be hung in the husband's office. I was given fabulous raw material to work with (the bridal gown, veil and headpiece, the wedding invitation, the sheet music used in the wedding, the vows, a receipt from the honeymoon that is their first signature as a married couple, a tiny ruby given to the bride by her father, and a number of photos) and permission to use them as I saw fit.
I used a 12"X12" museum canvas for the substrate and painted it in shades of ruby red (since ruby is the stone for a 40th anniversary, it seemed the most appropriate color to use). I changed all the photos to sepia, sized them to fit my composition, and transferred them onto skirt of the wedding gown. In order to include the invitation I needed to miniaturize it. I made an envelope for it and did not glue the invitation down so it can be removed to read the whole thing. I cropped one picture of the couple, did the math, and made it small enough that I could fit 40 copies of it onto the painted background in a checkerboard. The material from the wedding gown is just translucent enough to show the small pictures of the wedding couple that are covered. I antiqued one of the smallest floral elements from the bride's headpiece and placed the ruby there. I copied the prayer from their wedding service onto a transparency and included it also.
Contact me if you are interested in a commissioned collage.