What is a low-maintenance way to cover gray?

"For clients who are still looking for gray coverage, even though they can only come into the salon every 9-12 weeks, utilize a shade slightly lighter than their natural base color," says Beth Minardi, Creator of Beth Minardi Signature Color and Minardi Luxury Color. "First, I like to completely erase a majority of the gray strands moving throughout the hair lengths. I do this by first isolating selected strands in foil and painting them with a demipermanent crème shade at the same level as the client’s currently pigmented hair. After processing this for 30 minutes under heat, I shampoo the hair, rinse and thoroughly towel dry. The next step is to glaze all of the hair with a formula consisting of my demipermanent liquid acidic color. I prefer using a Level 6, 7 or 8 formula. Apply generously and evenly from the scalp throughout the lengths. Cover with a plastic cap, and process under a heat source for 20 minutes. The client will have a gorgeous shade- on-shade, effective blending of gray that will hold up for several months before requiring a retouch."

What is a low-maintenance way to cover gray?