Here's an interesting exercise based on a familiar Maj. scale pattern of (mainly) Perfect 4ths, transplanted & transposed to each step of Melodic Minor.
Re: A Perfect Fourth Story - Melodic Minor 4th Shape
Man, there's nothing like practicing patterns in 4th to really work your chops. Start with something as simple as scales in broken 4ths and move on to more complicated excercises if this is your first venture into working 4ths. I promise, it forces your fingers to move in ways you are not used to if you haven't done this kind of practicing yet. Have fun!