I actually trade players often, buying several at the beginning of each season and as needed throughout. I'm quick to bench players not performing well that day, and if their bad performance continues I don't hesitate to sell and replace them. Also I usually have high bonuses since I train so often. Even when I am the Away team I usually have 6-10% possession bonuses just from Fans (this sometimes does not include me too, since we all can't attend every match, no matter how hard we may try..). I really do try hard and dedicate lots of time to make sure my teams is top quality and I am prepared for each match.