From a performance standpoint, the first thing everybody should do is frre up the intake and exhaust. Even if you don't care about extra horsepower, we all want the feel of a happy motor. I used the CMW kit for the Electra. Seems to work good.
Appearence-wise, the best thing I did was to get rid of the stock seat and install the premium delux solo saddle and pad. The difference in looks was tremendous. Comfortable too.
I have also added a larger front cog and windshield.
Since I am the type that can't leave well enough alone, I think I'll get a better clutch, fatter tires, vintage tail light and turn signals... the list goes on.