I only shoot RAW

Nikon Z9: Extended Shutter Speeds (M), allowing directly selected exposures up to 900 s / 15 minutes.

Nikon Z8: has Extended Shutter Speeds (M) in its Custom Settings menu.

Nikon Z6 III: has d7 Extended Shutter Speeds (M).

Nikon Z7 II / Z6 II: both have d6 Extended Shutter Speeds (M), with Nikon explicitly stating that the maximum selectable shutter speed is 900 s / 15 minutes when enabled.

Nikon Z fc: also has an Extended Shutter Speeds (M) option in its Custom Settings menu.

My Nikon Z9 Exposure Setup

This is the approach I'd use on the Nikon Z9. The same general principle applies to many other Nikon mirrorless cameras, although menu wording and available display options may differ by model and firmware version.

Use a Restrained Picture Control

If I'm primarily shooting RAW and using the preview to help judge exposure, I prefer a relatively restrained Picture Control. Flat is useful because it produces a less aggressively contrasty rendering and is designed to preserve a wide tonal range in the rendered image. But there's an important distinction here. Using Flat doesn't change the underlying RAW sensor data in the sense of applying the Picture Control permanently to that data. Instead, you're changing the camera's rendered interpretation and preview.

Make the Histogram Easily Available

Rather than permanently covering the viewfinder with information, I prefer to have different shooting displays for different purposes. On the Z9, the shooting displays can be customised and cycled using the DISP button.

My preference would be: One clean display for composition. One information-rich display with the histogram for difficult exposure situations. That way you aren't constantly staring at a graph when you don't need one, but it's immediately available when the lighting becomes challenging.

Use Exposure Preview Appropriately

The advantage of an electronic viewfinder is that it can give you a visual indication of how your settings affect the rendered image. That's extremely useful, but don't make the mistake of judging exposure solely from how bright the viewfinder looks.

Treat the visual preview and histogram as complementary information. The preview helps you visualise the photograph. The histogram provides a more objective indication of where the tones are falling.

Keep the RGB Histogram Available in Playback

For difficult exposures, I also want access to the RGB histogram during image playback. This provides a more detailed check after the photograph has been taken and can reveal potential clipping within an individual colour channel that wasn't immediately apparent from the overall image.

Keep Highlight Warnings Available

The highlight display complements the RGB histogram. When the exposure is critical, use the two together. Histogram: what are the tones doing?

Highlight warning: where are the potentially problematic highlights? That's much more informative than simply looking at the photograph and deciding that it appears bright enough.

My Exposure Workflow

Once the camera is configured, the actual shooting workflow is straightforward.

Meter the Scene

For general subjects, start with Matrix metering. When retaining bright areas is especially important, consider Highlight-weighted metering.

For a very specific subject area, Spot metering may be more appropriate. The metering mode should match the subject rather than being chosen simply because one mode is theoretically more sophisticated than another.

Look at the Histogram

Don't worry about making the histogram look aesthetically pleasing. Look at the areas that matter. Where are the important highlights?

Where are the important shadows? Are those tones sitting where you want them?

Adjust Exposure

If necessary, use exposure compensation or change aperture, shutter speed or ISO, depending on how you're working. You're not necessarily trying to move the histogram as far towards the right as possible.

You're trying to position the important tones where you want them.

Take the Photograph

This sounds obvious, but there's a danger of becoming so focused on technical information that you stop concentrating on the subject. The histogram is a tool.

Check Critical Images

When exposure is particularly difficult, review the photograph after taking it. Look at both the RGB histogram and highlight warnings. If everything important is where you want it, carry on shooting.

Learn Your Camera's Headroom

There's one experiment I think is particularly worthwhile for photographers who regularly shoot RAW. Learn how your own camera behaves. Find a controlled, high-contrast scene containing important bright detail and photograph it at progressively increasing exposures.

Watch what happens to the histogram and highlight warnings. Then open those RAW files in your normal processing software, such as Lightroom, and examine how much highlight information remains recoverable. What you're learning is the relationship between:

What the camera warns you about and What your particular RAW workflow can actually recover. Don't assume there's a magic universal amount of highlight headroom. The useful lesson is understanding how your camera, your settings and your processing workflow relate to what you're seeing while shooting.

Once you've done that, the histogram becomes a much more meaningful tool.

So, Which Tool Matters More?

Neither replaces the other. The light meter is primarily a tool for helping you determine exposure. The histogram is primarily a tool for showing you how the resulting tones are being distributed.

With a mirrorless Nikon, they're particularly powerful together because you can use both while you're still composing the photograph. But there's one final point that's more important than either. Neither tool understands your creative intention. You may deliberately allow a bright window behind a portrait to go completely white.

You might intentionally allow shadows to disappear into black in a moody night photograph. You might underexpose a subject deliberately to create a silhouette. Those aren't necessarily exposure mistakes.

They're photographic decisions. The histogram shouldn't prevent you making those choices. Its job is to help you understand the consequences of them. That's the real value of these tools. The meter helps determine the exposure. The histogram shows where the tones have fallen. You decide whether that's the photograph you want.