Emollients can be applied as often as you need them. As a general rule, you should always apply more emollient than you think - people tend to underestimate the amount of moisturiser required.
Application of steroid creams is measured in Finger Tip Units (FTU) - the amount of cream from the end of the finger to the first crease. Typically, one FTU would cover the equivalent area of skin of one hand.