Just like offhand, the kneeling position has become a regular part of field target matches. I still spend time trying to perfect my kneeling position and find that it is an ever work in progress. I added an article to my blog about the kneeling position athttp://www.usfieldtarget.com. If interested, check it out and let me know what you think.
What I've seen is most fail to plant their knee firmly on the ground. They have their bum bag to far forward. In stead of offering support for just their ankle they use it to keep their knee clean. Knee on the ground, bum on the back of the ankle. There must be some void between the knee and foot or else your just sitting on your leg. Fill that void with a knee roll or your bum bag. You better have a dirty knee or knee pad at the end of the day!