It varies. I do mine seated and use a very strict form, so use 7.5kg. I get a nice squeeze at the top. I could probably double the weight if I varied how I did it.
I find with a lot of my shoulder exercises I stay light and go for the pinch at the top, and it's been working well.
gym about their form and giving helpful advice in a way that doesn't sound patronising... i decided to do it today.
The lateral raises hit the Lateral Deltoid, pressing is focused on the Anterior Deltoid.
My shoulder work is like this.
Dumbbell Shoulder Press (superset with behind the neck smith shoulder press)
Seated Lateral Dumbbell Raises
Lying Rear Delt Raise
Shoulder Press Machine
Cable Lateral Raises
Cable Rear Delt Pull
Essentially I do 2 exercises on front, middle and rear delt. I alternate them through the workout - front, middle, rear, front, middle and rear.
Upright rows 3x8
Shrugs (front + back) 3x20