First of all, if you spinned a skull, just have your left arm in the usual Kinect cancel position (left arm and left leg 45 degrees) and in the in-game menu that pops up you can simply restart the mini game without losing the 25 credits. Like in the other guide, the XBOX button works as well, but this is a Kinect game, so you are not supposed to play with your controller in it.
The wheel has numbers in the following order 100-1-5-1-1-10-5-1-20-(skull)-10-1-5-1-10-1-20-5.
Part of it is luck, but not everything, if you raise your hands and drop them with the slowest possible speed that the game still accepts, the wheel will stop 6 numbers from your current position (e.g. your first spin will always end up at the second 5). This strategy can be applied at any point, so it is always worth to watch where you ended up with your spin and what the 6th number ahead is.
Rest is luck, but if you practice the movement that gets you about a whole spin, you can get the difficult numbers (100, 20) upfront. By always knowing where you currently are on the wheel and where the good numbers are you can plan the speed you do your next spin with and mop up afterwards. Using the slowest spin to move 6 ahead was key for me after I have done 2 or 3 lucky spins.