Serendipity is a earth friendly technique!! You can use ANYTHING for your substrate!! You need light weight cardstock - consider junk mail, a card front or layer discarded because of a mistake, packaging from the recycle bin, covers from annual reports, catalogs and paperbacks, etc. The smallest I would start with would be 4.25" x 5.5" and 8.5"x 11" is plenty large!! For collaging onto this surface almost anything goes!! You need scraps about 1" in diameter preferably ripped so the edges are soft and easily glued down. In the way of paper, you can use old greeting cards, calendars, catalogs, junk mail, gift wrap, tissue paper, napkins, decorative paper, envelopes, paper bags, packaging, instructions, manuals, artwork, labels, etc. You can also consider adding lace, fabric, mylar, foil, tyvek, mesh, etc.
For these pieces I chose similar coloured papers from my "box for collage" - turquoise and blue for the one and purple and pink for the other. I ripped all the scraps into smaller pieces (1" or so) in uneven and random shapes. Armed with a tray of scraps, a glue stick and some discarded cardstock I started applying glue to the back of the pieces and gluing them down. Lay them next to each other or overlap them - whatever works!! Sometimes I tear the pieces smaller still to fill in gaps. Don't worry about going over the edges - that can be easily trimmed later. Really mix up the colours and texture - like pieces should not be adjoining!! Once you have covered the whole surface, double check that all the edges are well glued down and leave to dry. I would recommend over night to ensure all the glue has dried. It may not look fantastic when you are done -no problem because you can embellish it by stamping with colour, embossing with embossing powder, colour washing with acrylic paint, adding glitter, spritzing with shimmer mist, etc!! My favorite is to stamp with a script stamp and emboss with metallic embossing powder!! Works every time!! Once your collage is finished you can use it to make accents for your art by cutting it into any shape - rectangles, squares, hearts, circles, snowflakes (use a die) - whatever you want!! Straight lines means no waste!!
If you need a visual you can find tutorials here and here! If you would prefer a video tutorial check one out here.
So this weekend consider doing your bit for the environment and create a Serendipity collage while you are watching TV or listening to your favorite music!! Should you also be enjoying some chocolate, incorporate the wrappers into your collage - no evidence!!