Imagine you live in the old west. There are no cars and you must do without. This should help immensely. You can use gasoline more wisely, too. Use maps to assess the shortest distance.
Maps online are free.
Drive at an even speed, within the speed limit. Even speeds save gas and, remember, speeding tickets cost money and time. Take good care of your car and it will use gasoline more efficiently. Use top quality engine cleaning additives or try some hi grade gasoline once every few months. Try coasting on downgrades.