Down and dirty basic steps...
- Have the kids wear loose jeans, shorts or sweatpants so they can roll them above the knee.
- Bring ski socks, thinish ones that they will be wearing when skiing.
- Have them put the damn phone away, you need their undivided attention for at least an hour.
- Don't go by their shoe size, measure the foot ... in centimeters ... ideally before you leave the house.
- Do this sitting then also do it standing.
- If it changes more than 1 CM, they very well need some support and bypass swap and go straing to a real ski shop and plan on some support under the foot ie a footbed, at least a Superfeet.
- Kids are visual. Shell fits are tough for them to understand. Take out the stock basic footbed and put it up against the foot. This will show them that it (somewhat matches the foot in length) You don't want more that one fingers width past the toes.
- Put everything back together. Remember they haven't been in a ski boot for 6 months they will forget what it fits like.
- Before they get into the boot, I will remind them, "Remember when we just put your foot against the footbed? WAIT FOR REPLY.
- Good, now, when we put your foot in the boot, it IS going to feel too small, understood? AGAIN, WAIT FOR REPLY.
- Good. Initially, your toes will be against the front, I will ask you to trust me at this point and when we get you buckled in, and in a ski stance they will come back and you will be able to wiggle the toes.
- Boot Flex. Do not ask them to flex their knees, because by doing this, the butt can just come down. Ask them to bend their ankles to see if they boot flexes.
Remember, kids should grow out of gear and not into it.