Basically, you just push the exposure till it's almost blown out... You could take your shot, then experiment by adding more exposure by one step, take it again, then another step, repeat, etc. until you like what you get. Remember, your dof will shorten if you open the iris more, or you could get blurring from camera/subject movement if you slow down the shutter, but either technique would help you get the high key look... Or you could add more light if it's available. Hope that's not too much info, Cheryl.