One of the best tips I can give any prospective buyer is to make sure that when they view a property and they absolutely love it, that they contain their excitement.
If a real estate agent knows that you just got to have it, he or she will really make sure you pay top dollar for it. Show subdued interest, and whatever you do don't start measuring up where your fridge will go, before you buy the property.
Always advise the agent that there are three properties you are interested in purchasing at present, and that at the end of the day it will all come down to price.
If they ask you which properties you are looking at, tell them that you would prefer to keep it confidential. If they ask what price range you are looking at purchasing in, give them a broad range and tell them that it really depends on the condition of the house, to what price you would go to.
Hot Tip: Buyers be aware that the real estate agent works for the vendor not you.