Keep flies AWAY from outdoor parties! Use lavender oil on a sponge put it inside a can with a lid 24hrs prior the party. Open can enjoy your food w/out flies flying all over your food. You could make a few and spread them along your food display.
Natural Pest Repellent Use orange and banana peels to keep the pests away. Cut up banana peels to bury 1 to 2 inches deep in the soil around plants that are prone to aphid infestations to repel and remove aphids from the area. Organic Authority recommends placing pieces of orange peel around affected plants or creating a tear in the orange peel and attaching it directly to the stem of the affected plant.
Natural Weed Killer - Martha Stewart Eco-friendly choices ... Warm weather can coax weeds to pop up from the tiniest cracks in the sidewalk. But don't go for the weed killer. Douse them with vinegar, lemon juice, or boiling water instead. The weeds will likely shrivel in a day or so; resilient ones rarely withstand a second treatment.
i use this in a spray bottle as a wasp/hornet spray killer. The spray bottle squirts further than traditional wasp/hornet spray provides a safe distance for use. cheaper and more effective than traditional sprays.
An Effective, Nontoxic Fly Repellant "He explained that a clear bag of water with a penny at the bottom would repel the flies very effectively. He went on to explain that the “eye” of a fly is actually hundreds of eyes and the reflection of light on the bag of water keeps them away."