Step 1: Turn and squarely face a prospect when he begins to speak to you at your booth. If the prospect came to you, stop any non-business-related activities you are doing and give him your complete attention. If a prospect stops to look at your booth displays or information for more than a count of five, then approach her and ask if you can assist her. If you are currently speaking to a customer, have someone else assist the prospect or have a waiting area available that you can direct the prospect to while you finish with your current customer.
Step 2: Ask the prospect what you can do for him. Ask very concise and direct questions that should elicit quick responses. You can direct your questions at the particular information or booth display the customer was looking at, or if the customer approached you from the floor, ask which products or services of yours he was interested in. You are trying to establish the prospect's initial level of interest here. If he has a specific interest, you should proceed with qualifying him. If she has a general interest, then politely answer her questions, give her some information about your company, get her contact information and then let her move on so you can find a more promising prospect.
Step 3: Begin asking more probing and specific questions about the prospect's needs and how your product or service can help. At this point you should be able to begin recommending specific products that apply to the prospect's needs. This should help move the conversation in a more productive and sale-closing direction.
Step 4: Listen to the responses you are getting from the prospect to hear if he is giving any indication of where he stands in the sales process. If you can start to get the prospect to talk as though your product is already installed and working in her facility, the prospect is almost ready to be turned into a customer.
Step 5: Work through any stalls in the conversation to see if the customer has a specific objection to the sale, or if he is just not interested in your product. Questions that begin with the statement "So if I understand what you are saying ..."--which repeat what the customer has told you to get him to be a bit more committal--are effective at this point.