We had my little guy behind the boat early into 3 yrs old, real two skis, Connelly cadets with the plastic bar but hanging onto handle for real, not attached to skis. Thought I was quite resourceful and it was easy , comfortable for kid and the real ski sensation.... PADDLEBOARD.... kid in water deep water position dad lying on stomach on paddle board holding second rope just slightly shorter than kid line. Picture dad on right side of kid with rope in right hand extended. Rope is tracking on the left side of the tip of paddleboard so the board wants to angle off right , not into kids path. Left hand on kids right heel.
Boat takes off , only has to go very slow and your left hand keeps skis in position so they don’t get dragged out the front , nor do the fall on butt as skis stay underneath them. Once on plane , you slowly let go and just keep hand close for support. Once up and balanced kids ha e no issues with the direct contact with boat.. then once it’s time for support bar to go , it’s just a simple hand on butt to get balance point. No expensive trainers or boards required. Progression process was very quick and comfort of being beside him was great for kid.....and nervous mom.