How to maintain your players several seasons in your team?

[Grandef]

Yeah I do the same. I always do a plan with my sequence of the drills I want to use. With 19 yo I train 120% averages in the drills, with 21 yo I raise it 140% averages as it is still quite cheap then. So the best version of my player is with 21-23 years old.
With 25 again, I only do 120% averages again, and, like you said, I train a lot of greys. Because by then my player already has very good white skills to overall quality ratio and now I just care about him lasting longer so he can delay my replacement. Training a replacement for the first time is most expensive.

I also found pictures of the player how he looked after every training. I don't exactly know what I trained at which stage anymore unfortunately. I just know that with 25 I also trained a lot of grey and things like Piggy in the middle, Stop The Attacker, Hurdle Jumps etc.

Thank you, that's exactly what I do. I don't have old player with my account (level 7 now). Here are some of my players, the training is not finished yet: