Hello there,
I'm somewhat of a perfectionist and I like all my teams to win their respective leagues, Under 18s, Reserves etc. So with this in mind I made myself a few training schedules to perfect the stats of my players. I use the default one for Goalkeepers then I have Defensive Midfielders, Attacking Midfielders, Wingers, Strikers, Defenders. I will post screenshots of each in the near future so keep an eye on this thread. hope this helps, well, it will do when I've done the screenies. Also all the players in all of my squads i.e. under 18s and so on are all perfectly develop(ing/ed). Another tip is to make sure your under 18s and reserves play the exact same formation and tactics as your first team because then if you need a replacement player from either of those squads because say, one of your players got called up for international duty or sustained an injury for longer than expected then they will already be accustomed to the tactics and thus will perform alot better and their teamwork with your first team squad sill be second to none.