I find that to be one of the most important things. Mine will periodically go take a nap in the rocks in the middle of the day, probably because many of them are deeper water fish and don't like the light in their faces? Hiding spaces make them feel safe and that lowers any susceptibility to stress/diseases. I also keep peppermint shrimp and I frequently observe cleaning behavior while they're hiding in the rocks which also may be the reason they hide mid-day.
I think Lyres are an awesome choice. Mine are super eaters, very well behaved but not pushovers and they're model citizens. They're great. My LFS has a bunch of these and they have been there for a long time. That's where these guys came from. Very healthy and unblemished. They seem very happy and calm.
My question to anyone else more in the know is would it be safe to add 2 more female lyres? I want these to be the fish focus in my tank for obvious reasons as this is not a tank for tangs or anything larger like that.