Lately I've been working on some animation with a more realistic feel. It means there is a lot of time spent examining subtleties, and one thing you become painfully aware of is that when you're working on a piece that has lots of over lapping movement like a walk or run, its easy to loose sight of things. You can end up chasing little bumps and wiggles around in circles until you reach a point where you don't even know why they are there and what they mean. As your cycle gets nearer to completion it gets harder and harder to isolate the movement on particular parts of the rig.
An example might be in the movement on your characters shoulder, in my recent work I decided I wanted a sort of rolling action on the clavicle bone. I wanted it up higher as the arm swung forward and down lower as the arm swung back, creating a nice fluid circular motion. The problem was that with there already being animation on the pelvis twisting back and forth and bobbing up and down, four spine bones twisting this way and that and the arm swinging around it was really hard to see what that little clavicle bone was up to.
So here's the tip, I found the rotation axis for the clavicles up and down movement and then used the scale tool in the graph editor to ramp up the size of the curve and make the movement much bigger. Now the shoulder is making big over the top rotations when I play the cycle in the view port, with the animation still playing and the curve still scaled up I start to tweak it. With the movement so big I can see where the high point and low point in the movement is, and can see it I have the changes in direction happening as smoothly or abruptly as I want. Once I have the over the top movement happening as I want, I start to scale down the curve again with the animation still playing. Using the scale tool you can get the action to a size that looks just right, it may be lost is a see of overlapping action, but you can know that you have the movement you wanted in there and that it contributes to the believability of your movement. You can always scale up the curve again it you want to make further adjustments.