The most important thing when buying a new hockey stick is to choose the right flex and length for your age. Make sure to choose the right flex on the stick so that you can utilize the stick's power when shooting or handling the puck. 

You will also need the right fitting on the stick.
There is Left-fitting and Right-fitting. 

A left stick is when you have the stick on the left side of your body, with the right hand lower down the shaft, and the right hand on the tip of the shaft. 

A right stick is when you have the stick on the right side of your body, with the right hand lower down the shaft, and the left hand on the tip of the shaft. 

This applies the same to Hockey players and Goalies.