I touch wood, throw spilled salt over my shoulder, say 'white rabbits' first thing in the morning on the first of the month. Always look for a 2nd magpie. I have no problem with cats whatever colour, apart from the fact I am allergic to their fur. As a child we used to hold our collar when we saw an ambulance until we saw a dog, then we could let it go, Also as a child used to say 'pinch punch first of the month', the reply was 'pinch and a kick for being so quick'.
I always put a piece of silver out (on the windowsill) on new years eve, usually a 50p even tho I know they are not silver now, then bring it on on new years day, my Mum always did this and I follow suit. I think all these things are habit rather than being worried about what will happen if I don't do them..
KARMA however is something completely different, I DO believe 'what goes around comes around'.