Here are some tried & tested, and some recommended blends for politely saying 'buzz off' to those annoying little insects!

Moths - Camphor, Few drops hung in the wardrobe on a hanky or tissue.

Mosquitoes - Citronella, few drops on your pillow or 6 drops in 30ml Sunflower Oil applied to the skin.

Most Flying Insects - Lemongrass, 15 drops in 1 pint water, sprayed directly on the insect.

Ants, Fleas, most crawling insects - 8 Tea Tree and 7 Thyme in 30ml water, sprayed where they walk.

Pet Fleas - 6 Geranium, 5 Lavender, 4 Tea Tree in 30ml water, comb fur back and spray at roots.

Another one for fleas - Make a natural flea repellent by adding six or seven drops of the essential oils of rosemary, peppermint, eucalyptus, tea tree, and citronella to a cup of water and shaking well. Use a spray bottle to apply the solution to your dog's coat every other day. (Do not use this on cats―they are too sensitive to essential oils.) 

Spiders - A 1:1 mix of Clove Bud and Cedarwood essential oils, either place a few drops onto tissue, or dilute with spring water and spray where the spiders come in to the house.