As I've mentioned previously on many websites, etc., there are some basic structural features that can help in the elimination process when trying to identify moths belonging to the main subfamilies of the Noctuidae. Most can be seen with a 10x hand lens but it's sometimes easier with a binocular microscope.
The terminology is somewhat 'old school' - but it really does help.
Noctuinae: spined hind tibiae ('back legs') - don't confuse these with the spurs that most noctuids have at the junction between the various sections of the legs. They are chitinous spines poking through the scales on the hind tiniae.
Hadeninae: eyes are hairy when viewed obliquely.
Cuculliinae: eyes are 'lashed' (they have long cilia overhanging the upper part of the eye)
Amphipyrinae: none of the above but with large globular eyes.
Using the above one can eliminate the majority of the possible species and concentrate on the 'right' subfamily.