This is one part of bike maintenance that can take up hours of my time. I'll be sitting there, jostling the aero brakes to make sure that they're the same height/position and trying different angles of the handlebar before I'll be satisfied. I even take several looks to make sure that the handlebar is aligned as straight as possible with the wheel (even though I've realized that it's surprisingly natural to correct for even offsets of 15 degrees or more!).
On another note, does anyone have tips on doing this more precisely?