What is the best way to screw pvc to a 2x4?

[BkCountrySkrMO2]

should i pre-drill a hole in the pvc? should i go in through the top or the side? i'm assuming screws are better than nail.

 

[fouldsys]

screw up from the bottom but make sure your screws arent to long cause they will stick out the top. just enough so it goes through the bottom part of the pipe