I've tried several things with little success but so far it's working wonderfully.
1 quart water
1 cup dry Rosemary
Bring water to boil, add rosemary and reduce heat to simmer for 20 to 30 minutes. Fill container with 1 quart clean cool water, strain rosemary water into bottle, add lid and shake. Makes 1/2 a gallon. I then fill a little squirt bottle and spray clothes, hair, skin, shoes ... whatever (don't get into eyes, of course). I also spray the goats and dogs. It smells good and seems to work wonderfully keeping the mosquitoes away. I haven't been bit once since I started using it. I saved the used rosemary to make rosemary vinegar, which i use as hair rinse.
Homemade Rosemary Mosquito Repellent