At some point in every ride I'm thinking about this. You don't have to have rollers, just an ability to focus on the smoothness of your stroke, how evenly you put power down left vs right, where in the stroke do you apply power (I like to feel like I'm dragging each pedal a little over the top of the stroke to avoid the feeling that I'm pedaling in squares), ankling vs not on a climb, how high can I spin a cadence without losing good form/bouncing, how efficient/economic am I - is the rest of my body as still and relaxed as it can be, etc. etc. you get the picture.