The difference between something "good" and something "great" is attention to detail. 
Charles M. Swindoll

Given a group of goaltenders are roughly in the same age bracket & playing in the same category (U18, U15, Major Junior etc.), what really separates one from the other?  Sure, there will be differences in size & styles but, most will have similar characteristics to their game. So, then, the REAL SEPARATOR BECOMES THE DETAILS in their game.  Make no mistake, when a scout/recruiter/team GM puts their stamp of approval on a goaltender as a draft selection or as a successfully candidate to make their team, DETAILS are the determining factor. 

 
Unfortunately, far too often goaltenders neglect the DETAILS.  And, the result of not paying attention to DETAILS is to forgo long term success because they don't want to take the extra few seconds or minutes to do the drill or movement as best (not perfectly) they possibly can or as they are asked to do.  Or maybe they think they don't have to because they believe they are a top end goaltender at their level & really don't have to work on those things.  Better buckle up then, because the road ahead will be rocky. 
 
If professionals have to work on DETAILS, you probably should, at least, think about it 
 
So, what are these dang DETAILS?  
 
DETAILS are found in your off-ice training.  "That last rep doesn’t matter.  I’ll just do 9. After all, is there any real difference between 9 & 10." "Yeah, I can skip this work out and take in a movie with my buddies. I’ve already trained once this week.  Don’t want to tire myself out too badly, plus I can make up the work out next week."  "I don't really need to push myself hard, just make sure I'm not last in line".   
 
DETAILS are part of the things you do (or don't do) during your games.  Do you have the post totally sealed off every time you move into an RVH?  Do you always track pucks completely into your body/equipment and track the rebound (if there is one) out and away?  Do you lean your upper body in the direction of the shot trajectory when executing a glove save?  Do you bring your catching glove under & up when you trap pucks against your upper body?  Do you often shoulder check & scan the ice peripherally when opposition players do not have the puck in a scoring position? 
 
These, folks, are just a very small sample of the DETAILS that should be part of an elite goaltender's game.  To understand where all these details are, I suggest that every goaltender should, at some point early every season, sit with paper & pencil and list every detail of every save movement, every positioning movement & every re-positioning movement they use during a game.  (get lots of paper) 

 
Yes, the attention to DETAILS require discipline. But, understand that, from attention to DETAILS (or not), you develop habits whether good or bad.  And that strong, good habits formed from mindful attention to DETAILS are the foundation of a successful, elite goaltender.   Yet, day in and day out, goaltenders neglect to pay attention to them.  Hopefully YOU are not among THOSE