Randomizing your actions without an RNG

Any tips on randomizing without access to a random number generator?
I've heard some people using the second hand of their watch or dealt card suits (not sure exactly how that would work), do you have a way of randomizing when you have to without your RNG, say like when a live MTT?

If you raise 80% of the time, you range is broad enough from any position.
Or use say 20-60-20%. Shuffle the strength of your hand.
Consider making limping a no go area