Love the bungie-cord training-plus it is a lot of fun! Never kick with ankle weights!!!
Squats, monkey-walking, etc are all great for the legs too. In our Silat classes, there are postures called Deepaks which call for a lot of body-weight motion on a single leg-they are killers.
If you are going to do a lot of kicks, do them very slowly-that's good for the legs, core, and back.