Very easy achievement.
In the very first area of the game (not the tutorial because you can't get achievements there) the dolls are extremely slow. Before you can start this area you'll be asked to pick one of the diabolical pitches you can use. After that the first area starts.
Just keep throwing overhand to where the dolls are and you'll be fine. (I didn't even have to 'aim'. Most likely you won't either.) This will most likely also be the area where you get the cheevo for not getting hurt. If by any chance one of the dolls does get to close just kick and it'll rocket away.
Just finish this area and bleep, two cheevo's in the bag :-) Happy gaming.