I've copied a post I made on another forum:
I buy 10% permethrin goat and sheep dip at the farm store, dilute it to 0.8% (about 12 to 1) and soak the clothes in that. It is a lot less expensive and stronger than the spray on stuff. The 0.8% is based on what the military uses. A soak in theory works better than a spray because it penetrates from both sides of the cloth. It is not approved for use on human clothing, so I'm not advocating it, just telling you what I do and telling you it works very well. DO NOT FORGET to blouse your pants into your boots!!!
My enjoyment of the great outdoors has gone up immeasurably since I started wearing my "tick-proofs".
The military has been working on this a long time, with lots of money, and as far as I can tell, they really got it right. If you google up some of the tests they did, you'll see some impressive results. I would not want to be in the control group on any of those tests.
Permethrin works fine by itself for ticks. If there are mosquitos plaguing you, you should add DEET. If you do the full monte permethrin treated clothes and time release DEET, you will be in good shape. I rarely use the DEET, because my biggest problem is ticks and chiggers, but it is part of the full package. Using the time release DEET is important unless you want to reapply the stuff every two hours.