too many people overlook the importance of dry land training and becoming aware of your body and how you move. Also, its important to start at the foundation; these things are boring and painful and they dont associate them with skiing so a lot of people just skip over them and look to what ski will make them better skiers.....
1- is your body in the correct position. many skiers do not know how to get into the "ready" position. Many have muscular or skeletal issues that prevent this from occurring. You can fix a lot of this through basic exercises and most importantly, adopting a regular stretching regime. But, having awareness is the first step. A full length mirror is very helpful to use while doing exercises. My favorite ski drill is one-legged squats. it will show misalignment issues right away. I learned to do these during my many rehabs from various surgeries, they are the #1 prescribed exercise by my PT. you dont need to go more than 45* or even less to get good results. You might need to use ski poles to help your balance when beginning and its more important to use correct form than to be wobbling and using poor form. Focus on the form and also muscle recruitment and firing. According to my PT, a large % of people's muscles dont fire correctly or at all when doing squats. remember: heels, arch, toe (just like skiing too) try doing a couple sets of 15 on each leg and then on both legs. Dont be surprised that you are quite sore the next day.
2- Strengthening your core and cardio work, (always consult your medical pro 1st). its amazing how quickly you will break from correct form and movement if your core is weak (core includes back) and your cardio efficiency is poor. Once you exceed your VO2Max,(functioning above your ability to bring in O2) things will fall apart. It doesnt matter how strong your legs are. Your core strength works with your Cardio in that your diaphragm needs to be able to function while breathing hard. A solid core helps to facilitate that. Also, your core is your frame. if the frame is weak, everything else suffers. Another great reason for cycling.
3- Looking ahead. looking at the bump directly in front of you is skiing in the past. Your brain can assess the terrain, angles and all that it needs in ~.10th of a second (thank evolution for that for saving you from angry predators) so looking at the bump in front of you is literally holding you back, you are denying your brains ability to prepare for the next turn and the turns after. I put this in the dry land training section because you can develop this in your every day living and if you bike, its a great way to improve your bike handling as well. Start off by becoming aware of where you currently look and then start by carefully lengthening where you are looking. this also effectively gets your core to begin to turn towards the new turn (or direction) earlier making it easier to turn your skis. even subtle movements with a tipped ski can make dramatic differences and use much less energy.
4 Boot set up. Yep, you have heard it many times before but if your boots aren't set up correctly (meaning static as well as active movements) when you flex, the boots wont' direct the skis in the intended direction. For bumps this is critical. All movements afterwards are correctional to adjust the skis or direction you intend to ski. this is very inefficient.
Finally. watch that video I embed above. that movement pattern is not typical for most but is highly efficient and effective. I am still working on it but it is more fluent for sure.