Negotiation is 10% poker face and 90% preparation. While it's great if you can have a stone face it doesn't matter too much if you have done your research and preparation. Here are some tips to getting the best property deal.
1) Know your market.
You will never get a good deal until you actually know what one is. Negotiating with a real estate professional is not going to be easy, they know the sales process and they the rules. Most importantly they know the market, if the property is overpriced or under priced they know. They also know how much genuine interest there has been on the property. What you need to do is look at lots of properties, read about what counts as value. Talk about what is important to you. Also find out what it costs to build/repair or replace dwellings for your property. While you may not ever know if a property is hot or not, you will know the true value for it and can walk away when the deal doesn't fit.
2) Make the Agent your friend
Getting on friendly terms with your agent can benefit you greatly, for renting and for buying. Find some common interests with your agent, think hobbies, home towns, kids. A fresh pot of coffee and fresh home made baking when your agent comes to talk can help butter them up too.
3) Be prepared to walk away
If you want the best deal, be prepared to walk away. Use you research to make an offer fairly under the market value (based on your research) and taking into account whether the market is bear market or bull. Then shut up. What for the agent to talk first, then explain in painful and polite detail why you value the property at its current value. If you are not going in the direction you want politely suggest they call you if there is a change on their end and move on.
4) Have all your paperwork in order
If you are applying for a rental have all your paperwork on hand and have copies for them. Check what is needed and have everything there ready so you can complete the deal there and then. The last property I rented there was literally a line out the gate and I was at the front of it. I rushed through the property and was putting the squeeze on the agent before the second couple had left the entry way. Guess who is living at that please now, me!
5) Have your money in order
Do not go house hunting before working out your budget and getting your financing or cash sorted. You need to know exactly how much you can borrow, how fast you can get it and any conditions which could catch you up. If you need a valuation have that ready to go on a phone call.
If you're renting, have that deposit ready to go and also be prepared that you may have to pay rent on the property from signup. This could mean you need to pay 2x rent for a month. Have it organised and if you're comfortable, have it in cash (Note: I advise against this as it's a security risk to you).
Also have your ending tenancy notice organised for your current property. Have a moving company prepared, not booked, but someone you trust on hand.
Getting a great deal is a bit of a war, but with some preparation you'll be confident to hold your ground and feel good, without regret, about walking away when the deal doesn't feel right.