5. Being Unthinkingly Upbeat

Salespeople are generally very upbeat, and that's a good thing, but it's important that positive thinking is conjoined with critical thinking. This practice is needed to properly assess whether an opportunity is really there and to avoid complacency.

All sales managers should be assisting their salespeople to create tough questions that can lead to deals' closing faster.

Veteran salespeople assume they are losing until they win. Rookies think they're winning until they lose. Just because someone likes you doesn't mean it will lead to any sales.