Thank you for the opportunity to help you with your question!
The first technique is knowing your prices for the cars or having a device handy that can tell you. You will also need to know exactly what the sales rebates are that the dealership is offering. These two things will assist you in making an offer on the car you choose to purchase. The buyer must also ask about any dealer incentives. Most dealerships have them, but do not verbally offer them because if you do not take advantage of the dealer incentive, the dealer will.
Please let me know if you need any clarification. I'm always happy to answer your questions.