How to conserve gas?

I need some information on how to use as little gas as possible. Where I live and work, I NEED to drive, so quitting driving is not an option, and neither is carpooling it. I just need to know some good personal or professional tips on using as little gas as possible when I'm driving. Already, I put my car into neutral when I'm slowing to a stop sign or light, or whenever I will be coming to a complete stop I throw it in neutral to lower the RPMs and hopefully make it easier on my engine instead of slamming on the brakes. I also drive slowly and start up slowly whenever I drive. I avoid using my heating or air conditioning too unless I REALLY need it, and I save my batteries by turning down all the lights in my car and everything. What else can I do to make my car better on gas? The air filter is clean too, I just checked it yesterday, lol