It IS more rewarding figuring it out yourself. I just did so on that very one this morning, having found all the others in the demo first.
It seems the easiest way to find them is to destroy everything, and if that doesn't work, start swinging away at everything that isn't destructible but sticks out a little. If that doesn't work, you have to start looking for anything that sticks out a bit, like the single skeleton in the cave.
I was initially surprised at how tough that Terran Golem was. I ended up taking it on numerous times before beating it, something I wasn't expecting from a first boss battle. This game is going to suck up a lot of my time, I can see.