I've decided to abandon acrylic and stick with water-miscible oil paints so I've sprayed my Two Flowers painting with matte fixative as a barrier between the two paint types and I've begun to cover the berries with gray. I've added some depth to the berries on the lower right as well.
I quite liked the grisaille approach, so I've decided to work that way with this painting too. Of course, because there are different colors beneath the gray, the result is completely different. No matter. It's an experiment anyways.
By the way, using Krylon spray finish as a barrier is a trick I learned from the wonderful fantasy illustrator K.Y.Craft. Below is one of her paintings.
Kinuko often lays down her basic colors with watercolor airbrush, sprays it with the Krylon finish, then completes the painting details in oil. You can read more about her work HERE.