When buying or selling a home you, as a customer have an undeniably powerful tool on your side that you should utilize to its full potential; your Realtor. Right from the beginning of the whole process, take the time to sit down with your realtor and discuss what you as a buyer or seller expect from them. Just make sure your requests aren't too obtuse or nebulous. Take the time to go over every aspect of the sale from listing to closing and everything in between.
In order to make full use of your realtor's abilities, allow them some leeway to do what they do best.
At times during a typical sale or purchase it is quite easy for the buyer/seller to feel somewhat out of the loop as there are important negotiations happening between the two agents representing the seller of the home and the buyer. A good Realtor will keep you informed on what is happening in this process on daily basis.
Also spend some time in discussion with your realtor about their proposed marketing plan for your home if you are on the selling half of the equation. Its a really good idea for you to know all about this so that you can also pass along information about the property. Word of mouth is a great way to spread info on homes. Also, give you realtor a real chance to show their strengths, after all they are professionals right? If you allow them the time and range to really let their strengths play out, chances are your home will sell faster and for a great profit or you will get that home of your dreams at a price that is equally as attractive.