At the risk of sounding like a "porthole"- a nickname I lovingly apply to the followers of the movement guru, Ido Portal- one way to think about line/skill development is to go through these three stages:
Isolation-> Integration->Improvisation
With isolation we drill a specific movement pattern over and over again until it's smooth. That's our vault practice, for example, but any single movement counts. With integration, we chain together our repertoire of pre-practiced movements into a continuous line. Since we have cleaned up our single movements so well, the task is to put together smooth transitions between one movement to the next. No excess energy is wasted. Finally we have the improvisation part where we move continuously through our environment, mixing up the routes we've drilled in a spontaneous manner such that new sets of movements and lines are discovered rather than just pre-planned from the get go.
At any stage along the path, we can randomly drop into the coveted "flow state" of mind. Time may slow down or speed up. We become highly concentrated, forgetting everything else in our lives except what is happening right here, right now. The act of putting ourselves in situations where we must be so highly concentrated (to make a rail pre, to avoid falling on our head when tumbling) induces this flow state. This state feels so good and so meaningful, I think it's secretly the reason a lot of us are doing parkour at all, regardless of what our stated reasons may be.
I've learned that this state of mind comes up in most disciplines requiring us to pay close attention. In meditation, it can be induced simply by sitting down and following the breath! When I learned that little tidbit, I had a little crisis. Why bother risking my body throwing it around on metal,trees, and concrete when I can just sit and breathe? Well I chose both, and it seems that both practices are mutually beneficial. If we train inducing the flow state on the cushion, we can use it in daily life for the mundane things too. Additionally, we can apply the flow state to the entire skill development process from isolation up to improvisation instead of just waiting for it to happen randomly. Flow state and improvisation go hand in hand. Done right, the mover will drop in and out of the known movement patterns and the unknown just on the edge of their abilities. Some people live for that feeling, some people dive out of planes in wing suits for that feeling.
Wait a second, does anybody ever get to the improvisation part? Probably lots of people do, but it might be hard to find a video of it. Usually someone builds a line, drills it a ton until it is smooth enough to put up on instagram, then wipes their hands clean of it and moves on to the next clip. The improvisation aspect is one of the most important parts to me and most often happens when the camera is off. Once you become familiar with a location from training there so often, you can spend most of your time in improvisation mode, spontaneously discovering new routes. Your ability to improvise determines your adaptability to new environments as well. Flow and improv are the keys to making every session valuable regardless of whether or not you got the clip for the next video.
Finally once you've been training for awhile, the 3 stage distinction tends to blend together. Just drilling one movement can become an exercise in flow because every aspect of the way you move between the reps of drilling a new movement become part of the continuous "line" that you're doing. In a sense, every movement you do is part of one continuous line and you're always "training" so to speak. Of course, when you get distracted and stub your toe on a curb, you might not feel so flowy anymore. But seriously, even bails can become part of the process. Apply the the skill development process, orient your practice around inducing flow, and you'll never have a bad session.
