1. Make ur inventory full (for example split stones)
2. Go to a wood pile pull out ur pick axe and start to hit it
3. Now it will say "inventory full, can´t gather" ---> Ignore this and hit it a few times (The wood pile won´t be smaller)
4. In the next step you put the stones back together (to get space in the inventory)
5. Now make another hit on the wood pile and you will receive a huge amount of wood (depends on how many times you hit it)

NOTE: This works on nearly all items for example: iron ores or even animals
EDIT: Might be outdated by now (last time tested in rust alpha)