This garland is a combination of two star patterns.

The small stars are from: http://ellenbloom.blogspot.com/2009/12/garland-of-stars.html

The large stars are from: http://www.ravelry.com/patterns/library/grandma-twinkle

The latter I modified slightly to do my stars in 3 colours so they looked like these ones:
http://attic24.typepad.com/weblog/2009/12/advent-garland....

I found I needed to do some extra slip stitches on the last round to get to the right gap to start the double crochets and I also added a single crochet in the gap when switching colours between rows.
See my tutorial for these modifcations here:
http://allison.gryski.com/2010/12/tutorial-colourful-croc...

On the garland, I used 15 chain around the large stars and 12 chain around the small stars. Pictures of how I connected the stars here:
http://allison.gryski.com/2010/12/star-garland-ta-dah.html