I've recently gotten into backpacking and learned that the most effective way of dealing with mosquitoes and ticks in nature is Permetherin. https://en.wikipedia.org/wiki/Permethrin . It is intended for clothing and not the skin. The best way to apply it is to soak your clothes and let it dry. Spray on applicators are also available. Once it is dry, it is very stable and safe. It does breakdown with UV and washes, so…
Ticks can drop out of trees on your head, or attach to your hair when your head brushes past some leaves on a tree. Also, if your bare skin is not covered in insect repellent, that could also be a route that they get to the rest of your body. The most effective method of not getting bitten is not to go in to the woods at all.
your profile reads:
He who lives without folly is not as wise as he thinks. -- Rouchefoucald