Picaridin 20% is the only solution I have found that is non-toxic, smells really good, and WORKS.
Picaridin is mainly used against mosquitoes and horse flies now, but it was initially formulated for ticks, and it works VERY well for ticks (better than deet).
The 3.5-oz. Natrapel bottles at REI are 20% picaridin, that's what I usually buy. That's a liquid formula, that can be re-packaged into tinier bottles if you wish. (The bottle sprays the liquid, but is not an aerosol.)
Sawyer, Repel, and Avon Skin So Soft also make Picaridin solutions.
I have seen mini 1-oz. spray bottles, in Target? or somewhere, but they are expensive, per-ounce.
Read the bottles carefully to make sure you are getting a 20% concentration. Most of the old ones were only 7.5%.
Deet is toxic and will be partially absorbed through your skin and into your bloodstream. If Deet melts nylon, imagine what it does in your bloodstream?
My limited research suggests that Permethrin has a low toxicity for mammals and is not easily absorbed in the skin, but it is very toxic to aquatic life. If a piece of clothing is going to be wetted directly in a stream or lake during your trip, don't spray on the Permethrin. It is also very highly toxic to cats; do not spray it on while your cat is anywhere nearby.