Drop zones can be found all over the Alps but your best bet will be to find high points on the mountains or flat areas just before a big drop and stop there on them. Once stopped, use the binoculars by pressing
and any area you see with flashing black and white lines across the surface of it is a drop zone.
If you are within 1000m of it you can unlock it straight away but if you are not you can mark it by using
. This will give you the distance between you and the drop zone and so that you can easily move to within 1000m of it. Once you get the notification that you can now unlock it in the top right corner of the screen, stop again and use binoculars to unlock it.
You can mark multiple drop zones at a time so make it easier and do all the ones you can see from your vista before travelling to unlock them all.
Hope this helps. Any feedback appreciated