I'm on my 3rd season already, I think I got a good grip of the game but one thing that I can never understand is players skill development.

I've been training my players regularly but I can't seem to have my players level up. Even if I do individual training, still the players aren't leveling up, in terms of skills and stars.

So can someone guide me the correct way to train your players? It very rare for me to see the "your players just got stronger" notification. Mainly because I don't know how to train my players