When selling a car, find out as much information as possible about the vehicle to avoid being tricked by a more knowledgeable client. Don't refer to book values when estimating the price of a car, as book values are very different from market prices almost for every car.
Refer to websites such as eBay to get an estimated price, but view the prices for cars that were sold and for those that are still selling. Get the history of your car from an online service. If you can document your vehicle's service history, including providing information about the parts used in repairs and work orders, it can make a huge difference in the price you can ask. Detailing the car can also help to attract more buyers and to increase its price.
If you are selling a car online, take as many quality pictures of it as possible, and upload them with the listing. Include all the information about the car in its description, especially any issues, as the buyer is likely to find out about them anyway. If the description is too long, break it down into sections. Always include your phone number in the listing so that buyers can easily reach you.