How to find the secret recipes?

[Wuschel]

I've been playing the new DLC's for a while now, with and without mods and I can't seem to find the secret recipes anywhere? I managed to activate the lighthouse and also understood the Ent in the other corner but what do you have to do to find the recipes? No digging machine or cool weapons for me yet, it's a bit frustrating.
EDIT: does it matter whether game mode is tech tree or sandbox?

[Darke]

Tech tree will show the secrets as '?' boxes in the relevant levels, and sandbox should drop the recipes like all others.

I believe it triggers when you get the relevant items; if you kill golems/dragons/wyverns/ents/pirates it should drop the relevant items for the recipes and it'll give you access to them automatically in the tech tree from memory.

[Kubix]

OK

[Steve]

This thread was quite old before the recent post, so we're locking it to prevent confusion.