Your sales presentation should be a series of "small closes". If you have pre-qualified your prospect before the appointment, you can set an expectation of what you have to offer. Also ask questions and listen carefully to the prospects needs and wants, addressing those during the sales presentation creates "small closes" during the process.  If you gather information and your product addresses the prospects concerns, the deal should close itself.  If you sense resistance, go back to questioning and information gathering.

Stay away from "closing lines". Clients want a real person,,,not someone who has memorized a sales pitch.