I used to have the problem with breaking my hands too soon in my mechanics. To break my hands slowly while my front leg is on the way down, I over-emphasized the time. By this, I mean that I kept my hands together much later than the ideal, because I had the habit of throwing my arm backward, rather than a controlled arm-swing. This gave me the sensation of the timing of where my hands should be at that stage of my mechanics. Gradually, I could wait smaller amounts of time until I had a nice controlled arm-break.
This is probably very confusing to read, I appologize.