I was taught the alligator/crocodile thing like many others, but it never really stuck. For some reason (later in life), someone said "left hand, less than" as they held up their left hand to form a less than sign. That image sticks in my head a lot better.

Another thing that was particularly hard to get naturally was the ternary operator. It didn't sink in easily until Jon Skeet said pretend the ? is indeed a question. If the answer is 'yes', this will happen.