All of what they said. I've only had one genuine night time cruising experience and that was when acting as a cover boat for a APB course. It's quite "exciting" and turns even the most boring cruise (by day) into an adventure.
Light Discipline is vital if you are away from built up shores. You mention the Thames, so I guess you may need shades

. We were off Donegal so were relying on the moon. Personal torches were issued to all crew, as were lifejacket lights. Torch use was banned when under way as it ruins the helm's night vision. It was necessary to restrict the intensity of the forward facing part of the white nav light (bit of tape

) and obviously intrument lights went off, electronics dimmed to minimum etc. Even at that, I found the plotter very bright, if I was doing that often, I'd look into a photography filter to reduce the light even more. Red head lamps are very useful. I made an assembly with a 12v red LED, wire and plug that can be moved around the console or whatever, useful. Forget about spotlights, etc, they're only going to be a help when berthing or recovering.
If cruising in company, DO NOT travel the wake of the lead boat/s, if a MOB occurs, you'll nail them. Probably good advice in the daytime too