For those who have chronic insomnia, the bedroom space may become a trigger for insomnia through conditioning. The sleep environment is meant to be comfortable and facilitate sleep. It should be cool, quiet, and free of distractions. Ideally, you would not allow a television or pets in your bedroom. Bed partners may be disruptive and some people choose to maintain separate sleep spaces for this reason.
I haven’t seen a study that empirically shows that it’s helpful. There is certainly a false myth that we need eight hours of continuous sleep: I think it’s possible to have your sleep be a little bit broken up and be perfectly healthy—but getting that eight hours is crucially important. The thing is that the placebo effect in some of these polyphasic sleep methods runs really high.
Give yourself some dedicated wind-down time. It doesn’t have to be a full hour or an elaborate routine, but try to spend at least 20 to 30 minutes doing something that relaxes you before you try to fall asleep. That could be taking a warm bath or shower, changing into comfy pajamas and sipping a cup of chamomile tea. Or something completely different — so long as it’s relaxing to you.