A few notes:
1.) I left two hats found at the beach last since they take the longest amount of time to actually get.
2.) The two gold castles on the beach can only be built after getting 16 gold blocks and 24 gold blocks, respectively.
3.) The gold crate at the tower can only be built after getting I think 32 gold blocks.
4.) The one Red Hat located at the bridge of the hut is impossible to miss: it pops up after you raise the bridge with the barrel.