Qualifying the Client!! I've been doing this for over 6 mos. (I have a background in sales) now and I found out the hard way, if you don't get ALL the necessary information from the client you'll be spending a lot of useless time and energy with someone who has no intention of ever signing a lease with you. There are a lot of people out there that don't really want to get an apt. but want someone to show them around. I believe that's one of the reasons there's such high turnover in real estate, especially leasing.
That's something NO ONE ever tells you in this business. All they (employer) ever focus on is how much money you're going to make, which for the most part is a myth!