1. Show up before your lesson is supposed to start and have the aircraft preflighted and cleaned.
2. Show up at times other than when you are training to watch other students. I am learning A LOT by this.
3. Study, study, study. Even information that your instructor doesn't tell you to read. Of course, I count reading PPRUNE as studying.
4. Be serious in your flying, making every hour count. If I get sloppy with something (and at my stage almost everything needs work) I work on that maneuver until it looks good. Very good.
I know these sound like the basics and that everyone does them. Except that not everyone does them. I run across a lot of fellow students that show up for their lessons late, then complain that the aircraft isn't preflighted for them and that they don't get to fly for the full time they booked, etc. i.e. they treat it like it's a high school class as if it's the instructor's job to force them to learn what they need to know.
The funny thing is that it's not "working hard" at all. I enjoy absolutely every minute of reading, studying, cleaning the windscreen and especially the flying. Sounds goofy, I know, but I toil in the paper fields of insurance all day so it doesn't take much to excite me.