1. Best bait here is 1 tsp active yeast + 2 tbsp brown sugar + 1 tbsp molasses (treacle) mixed in 1 liter of warm water.
Paint at head height on lamp posts.
2. Hang up a white bed sheet on a warm calm night. Hang a bright light about 18"/45cm away from one side and wait.
Forage along any bright security lights.
If you can make a serious collection, so much the better, many of the larvae are unknown but that's far less of an issue in the UK
than it is in western Canada. The biologies are just better understood than over here.
I did just that in my Biology prof capacity, many years ago.
Moths tend to "drop away" in flight from a roost. Put the jar below them and your open hand above them.
In a collection, they actually bleach(?) or fade over the years. Disappointing.
PLUS, you 're looking at the biggest and most diverse group of the Lepidoptera with untold numbers of new species to be named!
Be prepared to be criticized and sworn at, during all hours of the night as you leap around with your nets and jars.