One thing thats an easy resort for a kilt thats gotten too big is to undo the buckles and move them back to accomidate tightening. Seems easy, but this is a tricky processs. Next time you see someone wearing a kilt with the sporran/belt loops mis-aligned to one side, you'll know what I mean. A kilt is a custom constructed garment that utilizes a formula for fitting its owners measurements.
The underapron is the key. Some kilts have the be........Sorry for the break-my wife just called and the car has blown a tire and I have to go take care of this. I'll continue this when I return. If anyone wants to share their tips on this subject, feel free.