You can use the hit/mis or trial and error method to determine the correct exposure or you can use a light meter. As demonstrated by Frank Doorhof the two former methods took at least three “tries” to get a good exposure. Using the meter was a one time deal – for each lighting setup. Once  proper exposure for the model is determined, the photographer can exercise creative control to blow out the high lights or balance them out with the subject.

I ordered a meter as soon as I got home.