The trick to get a perfect snowman is to make sure the body is bigger than the head
The head needs to be about 3/4 (three quarters) the size of the body.
You don't need to roll the snowball until it is as big as possible. You can make small snowmen too
I always find the two snowballs first and decide where to build it before I start rolling them.
I usually move the snowball around until my character can roll it along without it going off in all directions. Once you can "steer" the snowball in the right direction, just move it to the other snowball and then make the head.
Most of the time I smoosh my snowballs by accident because I am trying to do everything too quickly and am not being patient
I've got the full snow set from last winter, so now I just make them for fun. I send unwanted furniture to favorite animals that have a kind of "winter" feel about them.
Whitney (white wolf) has a snow carpet and snow walls for her house - it looks fab
Hopper (the cranky penguin) has other spare items of snow furniture in his house.