When do you checkraise?

[Macquarie]

I almost never checkraise. I know this is a bad thing since then a check can be read as sign of weakness. But are checkraises +EV in themselves? Can someone explain to me, or post some hands showing when and why I shoudl checkraise.

My current thinking is like this. if I have flopped a great hand, I'm more likely to bet out (or possibly check/call on super-safe boards). Why give away your strength? With a weak hand that I'm not sure of, CRing seems like an expensive way of finding out where you're at.