Use a long lens, red filter and hide at a respectful distance. Never block entrances or use flash near active badger setts.
Choose well-marked paths, tell someone your plans and carry a map. Avoid steep ground and dense undergrowth after heavy rain.
From brimstone to peppered moth, learn basic wing shapes and markings. A simple sheet and torch can reveal surprising garden visitors.
Match clear nights with moonless hours and open glades. Print or download charts that suit your latitude and experience level.