Easy money
Go into Club/Stadium Facilities/Stadium Expansion. Change the stadium type (rounded corners, oval; this will cost you money) and select "Build Stadium". Do this again (changing the stadium type, build it), and you will receive money. Do not do this if you are thinking about building a new stadium.
Morale
Always check the player status screen before you sell a player. If a player has a close friend on the team, this will cost a lot of morale. This could be disastrous if the remaining player is one of your stars.
