Get a good Assistant Manager. My team never reacts badly to my *** Man's press conferences and he is almost always right about the team talks too. I have to step in some time, but not often.
As Raikan007 said, rotate. I didn't do that much but as ManU I had to do it and now find that my team members are less likely to be complacent and more likely to be motivated or fired up.
Also, I may be wrong but being more demanding during home ties (expect a performance) and lesser during away ties (wish luck or for the fans). And don't use the same team talk again and again. The game itself tells you this.