The best settings for shaky hands?

I have the same problem and it makes some lenses pretty much unusable hand held. A monopod is a good solution for some of the time but you can't always carry one. There's an old photographers trick using a length of string, tie one end off to the camera and make a loop in the other you need to make the string just the right length so that you can put the camera to your eye comfortably with your foot in the loop. Then you can use the tension in the string to help steady the camera.

Using a faster lens is another solution but it can be expensive. My Sigma 150-500 is a case in point, I struggle to get usable images with it hand held because the weight makes my hands shake even more. I've got myself a DA*300 which is a bit lighter and is faster and I'm happier with it even though I lose the zoom range.