Tea tree oil doesn't keep bugs away. Insect repellent with Deet in it is the only thing that really worked but deet seemed to make me feel sick after a couple applications so I avoided it. Unscented soap is your best choice to avoid attracting bugs. I use pine tar soap and it doesn't seem to attract bug or repel them.

An old guy I met while fishing in Jersey told me to smoke a cigar...no need to inhale just hold the cigar and puff on it enough to keep it lit. It really did keep the mosquitoes and green head flies down to a minimum. I don't think anything keeps them away completely. While camping I had pretty results with citronella incense and smoking cigars to keep bugs down while sitting around the camp fire.