any leftovers (not waste,IMHO) i use as a scrappy border or scrappy binding.
save a piece for a pretty label too!
i do tend to keep any "like" leftovers together..like baby/child prints to make a scrappy quilt down the road.
your quilt is beautiful though!
i think i am reading your "waste" as the cost of the jelly rolls, meaning you could of paid less,buying less fabric from the company.