How to form patina on brass?

The Complete Metalsmith by Tim...(I can not remember his name) has
recipes for those of us that do not have good storage places for pee
buckets and saw dust (which takes a long time to patina, but does have
interesting textures). To get green spray with a mixture of ammonia,
water, table salt and sal ammoniac; you can sprinkle saw dust on wet
surface. Let dry completely with out aid and repeat the spraying 3-4
times.
To get blue put in a bag or sealed container like a cooler with a open
dish containing ammonia- also rub table salt or salt water on the
areas you desire blue. Leave in bag until you get desired effect. He
also has recipes for brown, red. You can use a torch to get similar
colors to patinas created by liver of sulfur.