This post is probably pretty obvious to many, but I am sharing it anyway.
I drive a lot lately as my grandpa is still in the hospital an hour away, my kids are in school, my younger kid swims and I still have errends to run. I do whatever I can to save gas.
1. Combine trips. I live out in the country. It is a 15 minute drive to get just about anywhere. I combine trips as much as possible. I go grocery shopping after I take my daughter to swim practice while I am in town. I do all my grocery shopping in one big trip and usually do things like get gas at the same time.
2. Accelerate slowly. If you punch it everytime you take off, you are using more gas than if you do a slow, steady acceleration. You should also try to maintain your speed, and though it can be tempting, avoid speeding. Most cars get optimum gas mileage between 45 and 55, so take your foot off the gas.
3. Public transportation. It isn't all that available where I live, but I do utilize what we have, which means my kids ride the school bus home in the afternoon. It is coming by anyway. Might as well use it.
4. Carpool. Again, not a whole lot of that happening way out here, but since my husband does go right by the school in the morning on his way to work, he takes the kids in the morning, and includes the neighbor kid. Not really saving gas since they would otherwise take the bus, but not wasting it either, and my kids get a little dad time in the AM.
Of course there are other things you can do. Keep your car tuned up. Make sure your tires are inflated to the proper pressure. Walk when you can, or ride a bike. Save a dollar and be a little more environmentally friendly.