Anyone have any Pinewood Derby tips/tricks?

when i was in the scouts, my dad would help me with the weights, he told me to put them towards the front,make the car as heavy as allowed. he also sanded the wheels to round off the tread (for less of a contact patch on the track)make sure when you put your wheels on that they are perfectly aligned. we used the dry graphite on the axles. i wouldnt worry about making it aerodynamic as they dont go that fast. one other thing i would do is take alot of time and put a cool paintjob on it. they usually have a trophy for best paint also.