low degree driver, stiffer shaft at the tip (if I remember rightly) and augmenting your swing, oh and tee it lower and use a smaller driver head as newer ones are all designed to get the ball into the air with a higher COG.
I've recently found that I am hitting my drives far to high. I spoke to my pro about it and he told me I had outgrown my current driver ( Callaway Big Bertha 460 ). This club is designed to get the ball up, i.e high loft, low centre of gravity and very whippy shaft.
So, if you have found that you are starting to hit the ball higher and you know your swing is improving, this could be the reason.
Over the winter I will be trying out new drivers to find the one that will suit me ready for next year ( although I already love the look of the new Callaway FT-iq !! )
If its a manufactured method you want for sudden conditions that may warrent lower trajectory, you have the answer already, I use this on windy days and on fairways when using driver to get the ball some distance in heavy wind.
Yes I do use my driver off the lawn!