I'm not sure what you mean by 'shake'....
The golden rule is to have the time setting faster than the zoom on the lens, and you are pretty much guaranteed to be 'shake' free - unless shooting something moving really fast and thus get motion blur.
For example, if shooting at 50mm, keep the shutter open for less than 1/50th of a second, or shooting at 300mm, less than 1/300th of a second.
Anything shutter speed slower than the zoom length should encompass a tripod.
Having said that I always find it easier to mess with the ISO settings and Aperture size to allow the shutter to work faster and avoid shake....