I used to work in a cafe that served ice cream, gelato & sorbet. You name it, I scooped it.
In order to get the perfect scoop you need 2 things: a cup/glass/bowl of hot water & a metal ice cream scoop. Dip your ice cream scooper in to the hot water & then scoop your ice cream until your heart's content. This works because the metal scoop heats up in the hot water & then can cut through the cold ice cream with precision.
If you don't have an ice cream scoop I suggest you get one (& if you have one you should use it) otherwise you'll end up with a lot of bent spoons. If you don't have a scoop or refuse to use one (ahem Chris) at the very least run your spoon under some hot water before attacking your carton.