From my experience there are 3 inputs for a sidehill maneuver, or getting up on "edge".
1) Weight shift. This can be done by simply shifting your weight laterally onto one foot without lifting the other foot off the board. Try this by having your feet tunnel width apart and shifting to balance on either foot.
2) Initiate a counter-steer. Nothing drastic but enough to force the sled to want to roll onto the ski being turned in. Not to be too technical, but picture a rod that runs completely through the sled from front to rear where the sled would be balanced to the point of spinning, this ideally would be at the mid-point of the bumpers for a good visual. The counter-steering effort should feel like the skis are helping to spin the sled on this rod in the direction of the counter steer and as aggressively as you are turning. This maneuver brings the controls to the rider for ergonomics and lack of exertion.
1 and 2 should create a slow speed roll to get the sled up on edge. Practice this on flat ground, road, etc. Work on slow speed control of these two moves to keep the sled on edge and then learning how to add more weight or counter-steer to actually navigate the sled where you want it to go.
3) Throttle input. I reserve this for last since it can counteract the first two if not in harmony with 1 and 2. If you are traveling at the preferred speed and then get the sled on edge, then the throttle can be used to accelerate a turn to the inside/turn up the hill, or by backing off the throttle you can flatten out your curve or let the front end drop down the hill. Be careful that you don't mute the efforts of 1 and 2 with too much throttle which would tend to flatten the sled out.
I pulled some stock photos off the old web for visualization. I realize that the photos only show wrong foot forward so don't let that confuse you. Also, #1 will struggle all day looking at the skis.