I decided to use the birch trees and some crops for skunks. Currently I need 10 more stick bundles and 8 more skunks.
Once I completed level 5 (only getting enough materials for each level, never working ahead Incase I decided to stop), I got enough of the "easier materials" (chicken mushrooms sticks cloth) for 5 of each item. I am now concentrating on the burning embers until I have 160 (enough for 8 of each nesting material).
Since I have a gold mine that keeps my nuggets around 45, I am doing the adventures when I have 5 goggles. Once I have all the embers (37 to go) and return from the last adventure, I will then concentrate on getting materials for 8 and keep trying for skunks (through crops).
Brushes are my bottleneck, but I'm trying to ignore that until they are all I'm waiting on (of course collecting from the camp as often as possible)