Doublesided tape, cutting mat, cutting knife,
a variety of magazines, folders, newspapers, wrapping paper,...
Cut out a piece of patterned paper from a magazine.
Turn it around and stick a piece of doublesided tape on it.
Cut along the sides of the doublesided tape with your cutting knife.
With a paper punch, you can also punch figures out of the strip.
Take away the paper from the tape and stick it onto a giftbox.