You might also try moving the buckles closer to the front of the kilt... say about an inch on each side? That said, I notice that you are wearing your kilt under your belly-- not quite how it was designed to be worn, hence the problems with how it hangs. Two sets of ten sit ups, every day for a month, will usually result in tightening your waist by about an inch. You might want to try that as well as kilt strap extenders/moving the buckles.