They offer too much information. In an effort to make an impression, they festoon their pitches with too many details. "They say, 'My product does 20 things, and I'm going to tell you all 20 and, hopefully, one of them you'll love,' " says Hoffman. No one has time for laundry lists. Be selective.

They don't show deference. "I can help you," amateurs like to inform their prospects. How presumptuous is that? Prospects may be founders of successful businesses or corporate executives; they are experts in their industry. Salespeople? They are salespeople. "Don't say, 'I can help you,' " Hoffman says. Instead, "Say, 'That's very interesting what you just said. A lot of our clients say the same thing. Let me tell you how we've helped them.' "

They lose sight of the goal. Inexperienced salespeople too often walk into a meeting without having a clear goal in mind. Sometimes the goal will be a contract, but more often it will be the opportunity to speak with the prospect's technical team or simply another, longer meeting. "Mediocre sales reps are happy with, 'Thanks for your time, and I'll be in touch,' " says Hoffman. "If you don't ask for anything, you won't get anything."