By deco squares, do you mean serendipity squares?
If that is what you mean, here is how I do them:
I take a sheet of card stock and either run it through a xyron OR start putting glue on it, and then just stick pieces of scrap paper all over the glue.
I use little torn pieces, little scraps of photos, mulberry, vellum, whatever I have and just glue them all onto the cardstock!
Than let it dry, i usually put a book on top, just beause I want them to be secure <img src="/images/graemlins/smile.gif" alt="" />
Then I cut them in whatever shape I want! I do not just do squares. I have made xmas ornaments for my scrap pages out of these! They are cute <img src="/images/graemlins/smile.gif" alt="" />
I usually try to follow a color scheme myself but have seen beautiful serendipity squares with no apparent color scheme!
These are so versatile, because you can use them for anything! I love doing serendipity tags personally <img src="/images/graemlins/smile.gif" alt="" />
HTH!!!!