This has been the system that i have used across each team(bar Dortmund, who had very good strikers after the second season but changed back later on). Small alterations made each season
Scouting:
For scouting assignments, i assign the scouts to scout in their nation or the one with the most knowledge if there is too many from that nation. For example, Sporting, i sent scouts to Portugal and Brazil
The criteria was Superb potential and U21 or u23
To filter through the players I made sure to look at attributes and needed a few attributes to be atleast 12 (if they are 18y/o, more leniency) which were, Technical, First Touch, Work Rate, Determination and dribbling(except CB's). If they have too many stats below 6, then i ignored them. And depending on which club, i set max Transfer value to be 20mill.
I would then scout these players for a week, then discard any that are below 3 stars and continue scouting like that.
There were 3 other methods i used to scout for players;
Method 1:
I used a filter that i believe @Rashidimade, which is,
U20, atleast 5 caps and 7.0 average rating.
Method 2:
I would look through the players we already have knowledge on
u21, scouted abilty at 3*(which i think is "good") and then i would scout and filter like above.
Method 3:
u21, scouted potential at 5*(sometimes 4*) and then i would scout and filter like above.