Start looking out for local sheltered patches of ivy blossom, especially those which can be visited after dark with a torch.
The theme for National Moth Night this year is ivy/ ivy blossom. Daytime searches or traps set on Thursday, Friday and/or Saturday
Looking first during the day is a good idea then you can avoid nocturnal visits to any stands of ivy which are covered with social wasps - they may also be there in numbers at night, indicating a nearby nest.....but there should be plenty of ivy around to investigate.
More information may be available on the Atropos website but it is undergoing some reconstruction at the moment so keep checking.
Atropos - National Moth Night