Get low.


Merckx style.


Moser style.


Obree style (beaten into submission by the UCI)


It seems to me that aerobars themselves don't make you faster. Aero positioning makes you faster, and you don't need aerobars to get into that position (see above). Aerobars make it possible to hold that position longer and more comfortably, but at the cost of added weight, degraded handling, and loss of BF cool points.