It's important to have alcohol free days, psychologically, because then you will know exactly how you feel about such things, mentally and physically.
At present, I can't go a day without alcohol, this is the 4th time I've been in this position, similar with cigarettes incidentally, although at different times. I digress, when you can easily have an alcohol free day without any kind of distressing thoughts or negative physical symptoms, I personally don't believe you're drinking too much.
Of course, prevention is better than a cure. Just like opiates and benzo's, it's best not to let it get to a stage where it's going to be extremely hard to return from.
If you realise that you're getting headaches at a certain time each day, constantly thinking about when is an "appropriate" time to have a drink, or constantly thinking about drinking, they're my own personal warning signs that I've got myself all fucked up again.