Brutal hamstring exercise [video].
This will punch your hamstrings right in the mouth. Set up with both knees bent, feet flat on the ground with a slider under one of your feet. Lift the foot that is not on the slider off the floor. Perform a single-leg bridge with the other leg. Once at the top of the motion, straighten the knee by sliding the foot away from the body. When the knee is extended, keep the hips on the floor, bend the knee and start again with the single-leg bridge.
Pullthroughs - a better way? [video]
This is a great alternative if using some attachment for the hands increases back pain or you find yourself pulling too much with the arms. Start by setting the pulley so it is around hip-height. Set the strap so it goes around the front of your hips. Set and brace your neutral spine position. Focus on keeping pressure through the heels and sitting back through the hips. To return to the start position, squeeze the glutes and push the hips forward. Avoid overextending the hips and straightening the body as this will cause you to lose your balance and fall back.