essential oil percentages in natural products

I am looking for input on the rate/percentage of adding essential oils to natural products..

to bath salts*- (in 8 oz portion)some say .5 % to 2 % max

to bath/body oil*-have heard 2% to 2.5%

to Sugar scrubs-

to air fresheners*-have heard 5 % to 8%

to facial spritz*-?

to natural perfumes*-some say a true perfume blend consists of at least 30% essential oils


info on the internet varies, so I am trying to gather as much info as possible...thanks to all!!!