A common misconception with kilts is that you have to wear this or have to wear that in this way. Well, the kilt is about comfort and freedom - so you are free to wear what is comfortable for you!

My personal taste is to wear boots, whether they be hiking, combat, motorcycle, or otherwise. I think this is because of the fact that they go up the ankle a bit, which works well with socks. If not wearing socks, I think sandals will work just fine, especially athletic sandals.