i got iker muniain and marcus berg few years ago (game time ) etc. they r the best in the game now. apply the perfect training for them. these 2 are easy, so strikers. however to enable other stats u may need to switch training a bit. i have arda turan (midfielder) so is magnificent but his shooting and finishing is horible, so i put his training as a striker to enhance his attackng attributes. if u think ur players r wonderkids, keep an eye on how they train and when u loan them out make sure it's not a big club that would use them as a sub or as backup for a better player. i loaned my wonderkids and get offers from fiorentina, ac milan etc. but reject obviously and choose a club like QPR, or in belgium, in switzerland, or like i do in turkey, egypt, qatar, scotland etc.
PS: i also use tug's training and it's fantastic. all my players r doing so good..
PPS: if ur players r failing, either training is wrong (i.e. u made a CM train as a winger etc. or a DF as a FB etc)..or ur game has a bug as few people claim.
HINT: when u change ONE player's training, the whole group using the same training (strikers etc) also alter their training, so be careful!!!!!