When I use flash through a white umbrella, I move the umbrella very close to the person, at a very low power: 1/16 to 1/64th power
The shadows are not the enemy, but a wonderful gift. Soft, low contrast shadows add deptrh to a person's face
I've also learned from several classic photographers like Dorothea Lange and Yousuf Karsh, that it is not necessary to see the person's face ! to be a portrait. Karsh created a stunning portrait of Pablo Casals with Pablo seated on a chair, facing away from the camera, and toward the corner of a 30 foot high stone room The sound reflecting in a large stone room must have been exquisite
Another people element is having a dark background so that their face is not obscured.
So with a flower in a woods, I sit down kind of "lotus position", and begin a conversation with the flower Is this your best side? And I physically move completely around the flower to find two things: one, the best place where the shadows across her face are enhancing her presentation; second, if her face is in the sun, or the dappled shadowy sun, then where is the best place when the background is the darkest. Hopefully both work together.
Places to try this out: The Kingwood Center in Mansfield is a diverse public garden of a wide variety of flowers, blooming a different times through the warm months. There are also several green houses, one for succulents, one for tropicals, another for orchids.... There's a $5 parking fee, but otherwise, free If you would like to go there with a small group of photographers, email me. Two to four of us pile into a car and go together, leaving about 7:15 from Delaware, so we arrive when the Center opens at 8am. This is also when they have just watered, and the mist and water drops are a delight. firstname.lastname@example.org
Let me know what works for you.