Aside from general "more air flow", and use a good HSF and paste, there isn't much more to be said, without knowing all the specifics, and having a picture or drawing with the data. That can best be done in the Cooling forum. They will need all the specifics however, to be really helpful.
Ambient air temp around the PC, speed of the fans, and the above mentioned pic or graph, showing what the temps are, where, inside the case. Everything comes into play. For example, you could have a great exhaust fan set up, but it won't help if the air intake isn't able to match it.