Something I picked up while watching a Pants are Dragon video though I've added some of my own why and what to do instead to the thought process.

As a jungler if you successfully gank a lane (get a kill or push the enemy laner out of lane) and your laner is low you will want to help them clear any enemy minions that are present so that your laner can go back to the Fountain to recharge and buy. This also has the effect of speeding (typically called shoving) your minions into the enemy turret to be killed forcing the enemy laner to miss getting the gold and XP from those minions and... Read More