IMO, one of the keys to guarding the eyes, or any other faculty, is to begin each day alone with God. By being more inwardly focussed, we are less likely to be unduly distracted/attracted by things outside ourselves. When we are disordered, we seek to draw the attention of other creatures and are far more likely to give creatures much more attention than is right. If left unchecked, we end up giving creatures part or all of the special, principal place in our hearts that is for God alone.
When we get snared by something outside ourselves, it is usually because we are not sufficiently recollected. In order to be sufficiently recollected each day, the wisest course is to begin each day well -- i.e., meditating, talking to God, etc. This is all the more important if we have to spend much time in the public places of this crazy world.
Modern life is FULL of things designed to distract us and keep us 'living' on the surface in everything. That is not where real life is found, lived, or increased.
Spend time alone with God, Spork. He will return your investment ten-fold. Godspeed :)