In addition to the great questions my colleagues brought up in earlier posts, I always ask of my students to speak up and let me know if they are cold, hungry, confused by my instructions, need a bathroom break, and most importantly remind them that it is their lesson and to please speak up early in the day to make certain that I am on the right path. We are all different in what we want or think we want. I specifically tell them to inform me if at any point I am skiing too much, instructing too much, drilling too much. I check in often about this.
While perfect practice is the best way to proceed, the key word is still practice. A willingness to keep trying a drill, or movement is critical to getting the most out of a lesson. I often see students get frustrated who can not accomplish a new drill within half a minute even if they are solid and fast skiers on blacks. To get something out of lesson it is helpful to go into it with a readyness to fail a few times before we succeed. Top level racers still spend a fair bit of time on drills and skills. These sometimes convoluted exercises point out where we have room to improve without the coach or instructor needing to say very much to help define the deficiency. It is not our goal as instructors to create a situation where a student fails. It is however part of the learning process to be challenged, and it can take hours to begin to master an exercise or a new movement. Many more hours than most of us will spend in a lesson or with a student. Therefore, setting intermediary goals can be really helpful to keep morale high over the season or the years.
One suggestion to maximize the benefit of a lesson, would actually be to take a group lesson rather than a private lesson if there are multiple people looking to save money by splitting one instructor. Or at the very least have each student spend a couple of hours alone with the instructor. The benefit of group lessons can be that the ability level is much better matched than in a private lesson shared between friends or family members of a variety of ages.
Last but not least to get the most out of a lesson, if it is a lesson where a parent is observing or participating with their child, it is important and helpful for that parent to resist the urge to take on the role of the instructor. Unlike many of my colleagues I actually find that adults and kids can learn well together. Parents can be incredibly helpful in the lesson situation as long as they wait for specific instructions and directions.