Here are some notes from a Contemporary Style Kiltmaker on waist height.

1) If you are "A Gentleman of Substance" try wearing your kilt high. The apron falling from the front of the stomach has a very slimming effect.

2) If you have a long torso and shorter legs wear the kilt higher. It helps balance the overall look.

3) If you are very young and very slim you can wear your kilt at low rise but on most of us it makes the kilt look too short and "skirty". The length of the pleats helps the kilt hang and move better and with a low rise the pleats look too short.

4) If you plan to wear a sporran and wide kilt belt wear the waist as high as you can. These items shorten the overall look and lead to the kilt looking short. The low rise, with a sporran also means the sporran is worn under the belly where it puckers the aprons making them look unsightly.

I go over some of these points in the video I did on how to measure for a Contemporary Kilt.
I try to get all of my customers except the young into a kilt where the waist is at least riding on top of the hip bones. This puts the belt buckle at the naval. I personally like mine to be a wee bit higher because I have a long torso. So I find that when worn any lower than the naval there is not enough Fell area to give a good appearance to the back of the kilt.

I think we need to quit thinking of where the front of the kilts waistband is and start thinking about where it is in the back. The back of the kilt should tuck into the back of the spine. This keeps the kilt in place when you move, holds the sporran strap in place, and gives a slimming look to the kilt.

My advice is to get the waist high enough that the Fell, or sewn-down and tapered area, is as long as you can. If you look at some of the photos, and especially Barb's, it is the Fell that gives the distinct "look" to a kilt that we all like.