Scrapbook, Etc. has produced LOADS of free downloadable collage templates in square, rectangular and photo sized (4x6, 5x7, and 4x8), along with video "how to" lessons on using these digital templates. Also, they have samples that show how each template was used! Fantastic free resources!
They also have free printable directions and templates for gift boxes RIGHT HERE.
The site is really amazing, with lots of great, free ideas and resources - check it out!