the traps i use in western australia
http://www.premaorganics.com/fly.htm
they are bloody good, not so good if u live in a small area, they stink, but can get 6 inches of flys in them in a few weeks
i use this purple spray called centrigen as well, its for horses but keeps flys away, spray it on the roo dogs ears, keeps the flys off her, makes her brindle colours turn red/purple like charlies av lol(not quite that bright tho)
also sticky strips are good, hang them up, catch heaps of flies
citronella is good, i found planting a citronella plant was good, rub the leaves on te