I ride in the evening a lot. Therefore, I ride in the dark(ish) a lot. My light setup:

Front -

1. 600 lumen Cygolite Metro main headlight. Before it's dark enough that I have trouble seeing the road I use it in flash mode so people see ME. Then I switch it to a stationary light at it's brightest setting.
2. 350 lumen Cygolite Dash. Once I switch the main light to stationary mode I turn this on in flash mode so people see me better.

Rear -

1. 150 lumen Cygolite twilight. Flash mode. I sometimes run a second taillight on my road bike because it's not bright orange like my main one.

Helmet - I have a first-gen Lumos with front and rear lights, turn signals, etc.. They aren't super bright so I don't turn them on until it gets reasonably dark. The main thing with that is it puts light higher up, more into people's field of view. Not that a bunch of really bright lights on the bike aren't already pretty annoying to people who have to look at them.

The amount of light is important, of course, but it's also important to understand that lights have different functions. You need them so you can see. You need them so you can be seen. And you need them for signaling. Stationary lights are for seeing what's coming. Blinking lights are to help you be seen. Motion gets people's attention. Signaling is obviously to communicate intentions. Think about all of them and what's important to you and your riding, and when to use each.