The picture you see here is of a recipe box that was covered with a photocopy of a sweater. In this case, even the photocopy was a fake because the original was not a copy of a real sweater, but of a photograph of a sweater as it appeared in a knitting book. My producer and friend, Linda Watson, photocopied a picture of some grass and used it to cover the top of a doll-sized table. Next, we experimented with enlarged black and white copies of Victorian-style clip art, which we cut out and glued to a chair. There is no real trick to all of these tricks.
Imagination is what is needed most.
If you will be covering a large area, it is better to make a number of copies of the item rather than to keep enlarging it. Better to keep it smaller and maintain the sharpness. If decorating furniture or some item with a detailed design, it is sometimes better to search for a place where the design can be cut and patched rather than worry about using the entire design. If you will be doing your own copying with a scanner and printer, do it on photo-quality paper rather than ordinary printer paper. It makes a world of difference in the end results.