This is what I do every season.
I see what area or position I'm weak at on 3rd line and down. Reason being the new players will never be better than 3rd or 4th line and that's only if they are a top ten pick.
It's really a crap shoot. Scout the larger amounts of players 1st durning the season because it takes longer to do the first and 2nd year. After that the number of prospect goes down to maybe 70 total for the Niger league like OHL!!
Scout the European leagues once the playoffs start. Reason for that is less players and you reveal more % of stats.
I drafted a 3rd rounder who in his 2nd season on the 4th line has grown from a 72 to 84. He's the fastest skater in the league hands down with a sweet shot. You can find some gems. I also draft strictly by the star system and not the potential rating.
Hope this helps
Goon