There is no one-size-fits-all strategy for negotiating. Your agent has experience in negotiations and will explain to you the many points of a deal that may be negotiated.
Price is not the only aspect of a real estate deal to be negotiated. There are many terms of an agreement that are open for negotiation, including: closing date and costs, amount of earnest money, types of financing, repairs to be made, decorations, furniture and appliances to be included, and the list goes on and on. Each house will have its own set of negotiation points and each buyer and seller will have things that are important to them. All of these things must be taken into account when crafting your negotiation strategy and your agent will help you do so. Its important to discuss the strategy before writing the first offer so that your first move plays well into your second, third and so forth.