Side to sided saves is a basic goal keeper drill to help keepers get warmed up or to work on making diving saves.
For this drill you need a large goal, a goal keeper, a cone on either side of the large goal, and a supply of balls.
The goal keeper starts in the middle and when they are ready they shuffle to touch a cone on one side. As they shuffle back towards the middle, the coach tosses a ball towards the goal for the keeper to save. Once the save is made the goal keeper gets up and continues to the other side.
Another variation could be done where the coach calls out which side for the goal keeper to go to rather than alternating back and forth.
Depending on the ability of the goal keeper and the intent of the drill (as a basic warm up or to work on diving saves) coaches can play balls in with varying degrees of difficulty to save.