Hello Jock, welcome to the forum.

The sporran belt is generally worn over the kilt belt. I wear mine so that the sporran belt at the back is just over the top of the kilt belt and as it comes round to the front it crosses over the kilt belt so that the sporran is well below the belt.

If the hands are crossed in front of the kilt with arms hanging down - that is about the right position for the sporran itself.

But - whatever is comfortable, cos comfort is what a kilt is all about!