I agree with Haider, the elbows do lead the way. And not only for lateral raises but so many other exercises. Keep the thought on the elbows, rather than the hands holding the DB's, when doing lateral raises. Keep a slight bend on the elbows also, which can reduce stress on the joints. And keep the little finger high and the thumbs nearly pointing down (as MesM78 suggest). Gironda style.
Actually there is a version of lateral raises where the exercises is started from a 90 degree angle. The DB's are held out in front of the body, like in the half way position of curls. Than the elbows are raised out to the side. As far as machines go: One of the main values of the original Nautilus shoulder machine was that the work load/force was directly on the elbows giving better focus on the delts themselves. (you can lose so much direct delt muscle action when doing an extension movement like strict lateral raises) You can mimic the Nautilus delt/elbow raise a bit by having a training partner apply resistance against the side of the elbow while you try to raise it up. Continual resistance throughout the exercise. It you do it right, the delts will feel it very much the next morning.
Lying sideways on a incline bench/or floor and doing one are lateral raises can work well. Starting with the DB in front of you and lowering to the back of you. Than raise to the front again. Good Luck.
