The DA40-180 has an IO360, and our SOP on that for takeoff is:
1) Full throttle, prop full fine, mixture (normally) full rich. This usually involves the RPM indicator showing between 2550-2700 RPM (I must confess that I don't normally spend the takeoff roll staring at the RPM indications
).
2) Once airborne, and established in the climbout, reduce pitch to settle the RPM at 2400, continue like that until at cruise alt and then adjust to whatever power setting you want.
On the few occasions I've needed to get from A to B quickly, I've just flown it at the climbout setting of full throttle, 2400 RPM, and full rich (this was in the UK at around 1500' so no real air density issues).
Paul.