My opinion is that other people I see, use wayyy too much weight and
sloppy form.
Slow down, use a weight that you can control; stop and hold the weight
at any point in the movement. And repetitions too. I shoot for 20 reps
even if that means dropping the weight after each set. But I think using
a lighter weight, one that you can truly control and focus on the muscle
with is the key, at least for me.
Working up and down the weight rack, even starting with 5 lbs and
working up and down the rack and ending at the weight you started with
and really really concentrating on the muscle is key. (This is where a
lateral raise machine shines.) Larry Scott for instance, did this for multiple
sets with very good results. Can't say he used the best form according to
me but I willing to guess he had a very good mind / body connection
and obviously the genetics to have great delts does not hurt.
The deltoids are a very small muscle (comparatively) so keeping that
in perspective and getting over having to use heavier than necessary
weights and the willingness to at least try slowing the movement down,
feeling the muscle working can go a long way to safely develop the
deltoids with lateral raises.
That has been my experience.
Hope this helps.