We haven’t tried these yet, but they seem like a good place to start:
Homemade, DEET free mosquito repellent recipes: http://wellnessmama.com/2565/homemade-natural-bug-spray-recipes-that-work/
I always recommend taking astaxanthin to prevent sunburn, but here are some homemade sunscreen recipes: http://wellnessmama.com/2558/natural-homemade-sunscreen-recipe/