I have a 3 key frames that define a leg turn for my Liger character. It is complex but looks great. Rather than use a switch I wanted to try actions so I have control over interpolation (ease in/out etc).
But how the heck to get it into an action???
What I did was to make a "storage" key frame in the timeline to "save" my original frame 0 point positions.
Then I just copy each of the the other keys needed for the leg turn one at time to frame 0 and THEN create my action by selecting all points and making a key frame for the action.
Once I have finished creating the action I copy my "stored" or "saved" frame 0 point motion back to frame 0 and VOILA! EUREKA! I go take a pee or have a smoke or a cup of coffee and bask in the glow of my genius...
... in reality I come here and waste a bunch of time.

-vern