Tactician, your mean is team construction or stadium construction?
About team building, in beginning of season, I try to looking for the highest player to buy. All player have price more than normal player. After half of seasion, I stop buy player and concentrate to training them up to 6 stars and sell old player at the end of season.
About stadium construction, I am building everything, no stop any day from level 1 to level 11. And this is my stadium
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Anything else?