Ive come lucid more then twice by cats in my dreams for some odd reason. Infact before I even knew about LDing I had a LD when I saw a cat swating at me.
…
I became lucid by looking at my foot and noticing my “toes were out of order”. My big toe was in the center, the 2 smallest were on each end and the other 2 flanked the big toe. I thought, “that’s weird, this has to be a dream”.
/me uses Phoenix Down*
Because this thread deserves more love.
I once got lucid by merging with a character who had just become lucid himself. 
Last night I was suddenly grabbed by the balls by an invisible person behind me…it scared the hell out of me, but did make me think “WTF! This better be a dream!”. Luckily it was.
I was outside at my grandparents house. Suddenly fairies started to appear. I eyed them questioningly. Either I was dreaming or hallucinating. “Well, that’s not realistic,” I said. Then one of my teeth felt loose. I felt it a bit and sure enough it came out. “Now it’s just being obvious!”
I dunno. I always find those cliché dreams funny ways of getting lucid. 
, in my first LD i was a chicken chased inside castle… so when i looked at my hands to do RC those weren’t hands but wings… So I became lucid…
Someone farted in a dream, I thought that it didn’t sound right and suddenly I’m lucid!