My goto light is the cygolite dart 350. Super light and super low profile - on a black bar it looks like the bike was designed with an integrated light.
It attaches with a silicone strap, making it more versitalie than any other light I have.
It is light and versatile enough to mount on my helmet without me really noticing it is there.
I use it as a daytime strobe (tire of cars not seeing me) and as a nighttime directional light on my helmet.

For really dark gravel/road/MUP rides, I use a 750 lumen or brighter light on my bars and on my helmet (1500 total)
(If its dark, I want a lot of light - if it is well lit 350 lumens is plenty).

https://cygolite.com/product/dart-pro-350-usb/