The key to sharp images in low light is learning to hold a camera steady is support. Like anything else it is an acquired skill which requires practice to perfect. The strategies I use for holding a camera steady are very similar to those used for firearms: the more points of support the camera has, the steadier your camera will be.

The method I use is based on the concept of unifying the camera with the entire upper body as a single mass, then pivoting at the waist like a tripod ball head to adjust the framing. Its based on fundamental physics: the greater the mass, the more difficult it is to move.

A camera held loosely in the hands when the body moves the inertia of the camera mass makes it lag behind pulling it off target as the body moves until equilibrium is reestablished. I try to "glue" the camera to my forehead and lock my head to my shoulders:

Feet:

Feet should be arranged in a martial arts style ready stance, spread at an angle under the body so it does not sway. Someone should be able to shove you from any direction and not move you.

Right Hand Position:

The next important point of contact is the right hand with the forehead. Grip the camera with the right thumb behind the body and rest the V of thumb and index finger against the forehead.

Right Arm and Elbow:

The steps above will cause the right elbow to stick out like a chicken wing. If held loosely the right arm and head will flop around, so using the muscles in the back pull the left elbow backwards. As the right elbow is pulled back you will feel it work to lock the head into position on the shoulders, unitizing the mass of the head and shoulders as a single unit

Left Arm Position:

Put the left elbow in against the chest for support and cradle the base of the camera lens with the left hand.

Create Dynamic Tension:

The camera is held steady by creating dynamic tension between muscle groups. To unitize the camera with the head and upper body pull the camera towards the face so the right hand holding the camera is firmly against the forehead.

Pivot at the Waist:

When the steps above are executed properly everything below the waist is immobilized by the balanced stance and everything above the waist is unitized with dynamic tension of the arms pulling the camera towards the head with has been immobilized by locking the right shoulder joint with the back muscles. The waist becomes the pivot point, like the ball head on a tripod. Move the upper body at the waist to adjust framing. With this unitized position you will find it is easy to pan or shoot relatively well connected panorama sequences by simply rotating at the waist.

Breath Control:

The rise and fall of the chest during breathing will cause the camera to move. Deep breathing from the diaphragm (let your stomach below the rib cage move instead of the chest) will minimize chest movement and also improve the ability to hold your breath comfortably. When preparing to shoot take a full breath, exhale about half-way and hold it, tightening the abdomen.

Smooth Shutter Release:

Keep the act of pressing the shutter as smooth and effortless as the action of a leaf falling off a tree.

That's a line from Zen and the Art of Archery used to describe the moment of releasing the arrow as being an unconscious act of "oneness" with the target. I've done archery and competitive pistol shooting and have found the mental image of the leaf falling to be very helpful. Even with the best technique the sight will wander around the aim point and it seems the more I'd consciously try to keep the bow or gun steady the more it would move. With practice I learned to use sound technique to minimize the amount of wandering of the sight, but rely on my sub-conscious and let the brain tell the fingers when to release the arrow or pull the trigger.

The same approach works well with a camera, especially when using long lenes.

Stay On Target For a Count of Three:

A problem encountered with a gun is re-coil. The brain, expecting it, will brace for it sub-consciously causing movement as the trigger is pulled. There is no recoil with a camera but same reaction can occur because your brain may be thinking about the next shot you plan to take. From pistol shooting I learned to try to hold focus on the target for a count of 1-2-3 before disengaging and have found that it also help reduce shake when shooting with a camera.

The technique above might not work for you, but the concepts underlying it such as unifying mass, dynamic tension, and inertia should help you to find ways to improve how you hold the camera steady. There is no substitute for practice. Shoot and see how low you can go with the shutter speed. Set a goal, then try to better it. The more you practice the better you will get, and more importantly you will have a better understanding of what your limits are with different lenses.