Instead of only doing figure 8's in the parking lot, try doing a small circle about 3 times around in the same direction, then alternate. It's a slightyly different skill than a figure 8. Then do some slolum type zig-zags as well. And of course keep practicing mounting and starting, and stopping and dismounting. Way better to do all this in an empty parking lot and get your wobbly-ness over with there where you're safe.
Lisa