Chickens greatest protection is not to be seen by hawks in the first place.
I spent years evaluating risk for a living before I retired to my dream life as a farmer. I guess the threat analysis is still on my brain because I look at my hens' safety much like a risk assessment. I started with the strategic goal of having very happy hens who do not feel threatened, live a long life, lay a lot of eggs and go about their business enjoying making rich compost and fertilizer.
There are many threats to chickens in my area associated with predators. We have black bears, panthers, bobcats, neighborhood dogs and cats, coyotes, hawks, racoons, eagles and possums. They also have threats related to a dirty coop, cold, overheating, and from each other. I mitigate risk from all but hawks and eagles by having a fenced yard, trimming one wing and having a large safe coop with abundant resources.
The hawks in particular are a very threatening predator. I see them fly over daily and they will often sit on my fence watching the hens. My hens though really go about their business because they have numerous safety zones. Each area relates to an area my hens enjoy. Their coop is completely hardened with hardware fabric 1/4-inch with 1/2-inch fabric underground. The run is fully protected with bird netting and fully fenced.
The areas in the fully fenced acre do not lend themselves to having bird netting overhead. Instead, I use plants. I get down to chicken level and make sure all overhead trees, rooflines and open sky areas do not have an easy way to attack the hens. Cattle panels bent into trellises, a bushy island oasis near the pasture, a nesting box area that has large protective shrubs. All of these serve to protect the hens from dangerous overhead threats.
Blackthorn bushes with the lower branches trimed back to the trunk are excellent.
Large Roemary bushes worked well.
Any large bushes under trees make excellent shade and cover.
Great advice in the video.
If one could just persuade people not to cut and strip the ground they are going to fence around for the run it would be a start.