Another one from my trixie bag of tricks.
Have you noticed how difficult it can be to focus when you are in a dark environment? I notice that on my high end Canon cameras, not only does get focus slow or even impossible; it also gets inaccurate. Not good.
You have also seen that I use the Honl photo range of flash accessories, such as the Traveller 8 softbox and the reflectors and grids. And like the speed strap around all my flashes.
And here’s an all-new use of that speed strap:
When it is dark, I use a spare speed-strap to temporarily tie a cheap and simple LED flashlight to the flash. It aims forward and I can now focus:
Of course you will want to make sure that the light does not show in your pictures as it does in the photos above. I use this when I am using flash, and ambient light is “turned off”. Or I turn off, or redirect, the flash after focus.
Alternately, you can ask an assistant to aim the flash. But then you need an assistant.