As one of the posts above says, a lot of Rafa's issues aren't financial.
Get deals done early in the window.
Don't mess about with targets who could go elsewhere.
If you know player x is leaving, sell him ASAP, so that resources can be reinvested.
If you know player x is likely to leave but hasn't yet gone, don't use it as an excuse not to replace him.
Don't haggle over small amounts on key targets. Its a bigger risk NOT signing them.
Scrap the "never pay decent wedge for players over 28" rule.