You will need:
Fruit, overripe or rotten
Bowl
Scissors
Plastic wrap
Toothpick
Peel the fruit and chop it. Put it in the bowl, and cover it with the plastic wrap. Stretch it tightly over the top of the bowl. With the toothpick, make holes in it. When the trap is full of flies, place the bowl into soapy water for several minutes in order to destroy them. Then, wash it and use it again.
Lavender Essential Oil
Lavender can also serve as a potent fly repellent, due to its intensive scent. You can use it on a sponge, and make it spill-proof.
You will need:
Lavender essential oil
Sponge
Jar or can with a lid
You should apply several drops of lavender essential oil on the sponge, and then place it into the jar. Close it tightly, and leave it for several hours or until the next morning to concentrate the smell.
Then, you can open it a bit and place it wherever needed in the house to keep flies away.
Additional tips:
The bowls in which you place the rotten apples should be cleaned well as they might start smelling disgusting
Before use, wash the Mason jar with hot soapy water
You can also use eucalyptus and citronella essential oils to repel flies and other insects
Prepare a potpourri of the dry herbs of peppermint, lavender, and lemongrass and effectively deter flies
If you have a garden, you can plant lavender, lemongrass, and peppermint, and have them always at hand
Source: womanpositive.net